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Developing ecological control technologies against the fall armyworms (FAWs) is crucial. The ecological role of green manure crops has gained attention for their indirect contribution to enhancing crop resistance against specific pests and diseases in rotation systems. We hypothesize that green manure application directly affects FAWs host utilization. By using two-sex life tables, we measured the host adaptation of FAWs to hairy vetch and their offspring's adaptation to the original host (maize) as breeding generations increased during larval stages fed on hairy vetch. When FAWs' adaptability to maize was significantly affected by feeding on hairy vetch, we used 16s rDNA sequencing to detect the gut microbiota composition of current generation of FAW populations that fed continuously on either hairy vetch or maize. Our results suggest that continuous feeding of FAWs on hairy vetch does not enhance their adaptation to the host plant across generations, indicating no increased risk of damage to hairy vetch in maize-hairy vetch rotation. As successive generations of FAWs fed on hairy vetch, their host-specific adaptation to maize decreased or even lost, which was shown by a decrease in pupal weight and fecundity, as well as an inability of emergent adults in completing mating. FAWs' gut microbiota exhibited lower diversity when fed on hairy vetch compared to maize. Cyanobacteria were not detected in "Hairy_vetch" group, while Oxyphotobacteria_unclassified, Acinetobacter, Pseudomonas, Serratia, and Klebsiella showed significantly differences in abundance between the "Maize" and "Hairy_vetch" groups. Additionally, gut microbial taxa and FAWs performance were significantly correlated. Overall, the feeding experience of FAWs on hairy vetch resulted in a reduced or was lost maize-specific adaptation, as shown through changes in gut microbiota. Our study provides experimental evidence for the ecological role of maize-green manure rotation systems in pest management. [ABSTRACT FROM AUTHOR]

Ken joined the Potato Association of America in 1973 at the beginning of his career working with potatoes. Mike has co-authored more than 300 diverse potato publications and presented over 500 potato presentations to varied audiences. Dr. Ingham has spent much of his career working with various colleagues on nematode problems in potato caused by Columbia root-knot nematodes (CRKN) and SRN which vectors tobacco rattle virus to cause corky ringspot disease (CRS). Graph B Russell E. Ingham b Dr. Russell E. Ingham is an emeritus professor in the Department of Botany and Plant Pathology at Oregon State University in Corvallis, OR. [Extracted from the article]

Spinach has been suggested as a potential rotation crop for increasing crop yield by enhancing beneficial fungal microbes in continuous monocropping. However, no research on the use of spinach as a green manure has been reported. Thus, we tested the effects of spinach and Korean mustard cultivars (green and red mustards) (10 g pot −1) as green manure on soil chemical properties, pepper productivity, and soil microbiome of long-year pepper-monocropped soil. Spinach improved the soil nutrition (e.g., pH, SOM, TN, NH4+, and K), weed suppression, and pepper growth. Spinach had by far the highest fruit yield, over 100% pepper fruit yield increment over the mustard green manures and control. Our study showed that the major influencing factors to cause a shift in both bacterial and fungal community assemblies were soil pH, TC TN, and K. Following green manure amendment Bacillota, especially Clostridium, Bacillus and Sedimentibacter, were enriched, whereas Chloroflexi and Acidobacteriota were reduced. In addition, spinach highly reduced the abundance of Leotiomycetes and Fusarium but enriched Papiliotrema. FAPROTAX and FUNGuild analysis revealed that predicted functional profiles of bacterial and fungal communities in spinach-amended soil were changed. Spinach-treated soil was differentially abundant in function related to hydrocarbon degradation and functional guilds of symbiotrophs and ectomycorrhizal. This study contributes significantly to our understanding of how the soil fertility and soil microbiome alteration via spinach green manure application as a pre-plant soil treatment might help alleviate continuous cropping obstacles. [ABSTRACT FROM AUTHOR]

Incorporation of plant biomass into soil as green manures can reduce soilborne diseases and improve crop and soil health in agricultural ecosystems. Soil microbial communities can mediate beneficial effects of these amendments, but their response to different types of green manures is poorly understood. This study tested the effect of green manures from broccoli, marigold, and sudangrass on taxonomic and functional characteristics of soil bacterial communities. Green manures were amended to field soil and maintained in microcosms artificially infested with the soilborne plant pathogen Verticillium dahliae. Lettuce seedlings were transplanted into green manure amended and fallow soil and maintained under growth chamber conditions for 12 weeks. Bacterial communities in bulk and rhizosphere soils were characterized using nanopore sequencing of 16S rRNA and shotgun metagenome libraries. Under microcosm conditions, all green manures reduced the abundance of the soilborne plant pathogen V. dahliae and altered the taxonomic composition of bacterial communities. Twelve weeks following amendment, green manures had differential effects on lettuce yield as well as the taxonomic diversity and composition of soil bacterial communities. In addition, multiple green manures increased the abundance of bacterial functional traits in rhizosphere soil related to iron and polysaccharide acquisition and decreased the abundance of functional traits related to bacterial protein secretion systems. This study demonstrates green manures alter the taxonomic composition and functional traits in soil bacterial communities suggesting these changes may impact beneficial effects of green manures on plant and soil health. [ABSTRACT FROM AUTHOR]

Background: Rice (Oryza sativa L.) production, such as farmers' livelihood and the soil quality, has been identified to be strong influenced by climate change in China. However, the benefits of low carbon technologies (LCTs) are still debatable in rice production for farmers, which have been identified to tackle agricultural challenges. The choice of potential LCTs relevant to the case study is based on a literature review of previous empirical studies. Thus, the objectives of the study were to (1) investigate the public perception and preferences of LCTs in rice production of China, and (2) analyze the influences of the factors on farmer's decision in adopting LCTs in rice production. There were 555 farmer surveys from eight representative rice production counties in HP province of southern China, both the Poisson estimators and multivariate probit (MVP) approach were applied in the study. Results: Our results show that water-saving irrigation, integrated pest management techniques and planting green manure crops in winter season were the three major LCTs adapted by farmers in rice production. The intensity and probability of LCTs adoptions were influenced by the main factors including farmers' education level, climate change awareness, machinery ownership, technical support and subsidies. There is a significant correlation among the LCTs, and the adoption of the technologies is interdependent, depicting either complementarities or substitutabilities between the practices. Conclusions: This study suggests that policies enhance the integration of LCTs would be central to farmers' knowledge, environmental concerns, technical service and financial support in rice production systems in China. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate yield responses of four potato (Solanum tuberosum L.) cultivars ('Russet Burbank', 'Shepody', 'Gold Rush', and 'Russet Prospect') and soil N dynamic changes to two 3-year rotations in Prince Edward Island, Canada. The two rotations were the local industry standard potato–barley (Hordeum vulgare L.)–red clover (Trifolium pratense L.) rotation (PBC) and an alternative potato–soybean (Glycine max L.)–barley rotation (PSB). All potato cultivars received 170 kg N ha− 1 input at planting without irrigation. Soil mineral N content before potato planting was significantly higher under the PBC rotation. However, the PBC rotation produced significantly lower yields, suggesting the possibility of excessive N supply from the plowed-down red clover. While cultivar and the interaction between cultivar and rotation did not show a significant difference in yield, yields of all cultivars were positively affected by the PSB rotation. The Gold Rush cultivar was affected the most (36%), followed by Russet Burbank (17%) and Prospect (14%) cultivars, with Shepody being the least affected (3%) by the alternative PSB rotation. Russet Burbank was the highest yielding cultivar under both rotations. With the three russet cultivars combined as a single russet cultivar, the PSB rotation significantly increased tuber yields, while the Shepody cultivar did not significantly benefit from the PSB rotation, suggesting that the russet cultivars responded more sensitively to the alternative rotation. Results demonstrate that adequately accounting for N supply from a preceding green manure crop is required for sustainable potato production in this humid temperate region. [ABSTRACT FROM AUTHOR]

Green manure can sustain agricultural production, preserve biodiversity, and mitigate soil degradation caused by long-term application of chemical fertilizers. Moreover, the application of green manure can improve soil health through increased soil biological activities. Nevertheless, little attention has been paid to the effects of leguminous and non-leguminous plants on phosphorus- and carbon-related enzyme activities and fungal community composition in soil. In this study, a pot experiment was carried out to elucidate the effects of two green manures on plant growth promoting potential, phosphorus- and carbon-related enzyme activities, and soil fungal community composition. Two green manure treatments (Brassica juncea and hairy vetch), poultry compost and control (no amendment) were applied and soil samples were collected after incorporation of green manure and after plant harvest. The results revealed that plant growth with hairy vetch was significantly higher than that with B. juncea and poultry compost, and soil enzyme activities were markedly higher with hairy vetch than with B. juncea. Both green manure amendments altered the soil fungal community composition. It is possible that the incorporation of green manure into soil and their mineralization and decomposition were controlled by the carbon: nitrogen ratio of the manures and that these manures were easily degradable by soil fungi. In particular, the incorporation of leguminous (hairy vetch) green manure with a low carbon: nitrogen ratio resulted in better plant growth through fast mineralization. Our findings suggest that green manure incorporation is an effective practice and provides substantial benefits to the soil–plant system. [ABSTRACT FROM AUTHOR]

Some reports on mineral elements and fatty acid compositions of different legumes species have been published by several researchers in Turkey [[4]-[15]]. Therefore, this study was aimed at determining fatty acids and mineral element composition of narbon vetch lines to establish nutritional value for breeder and producers. Unsaturated fatty acids such as oleic (18:1), linoleic (18:2), and linolenic (18:3) acids, which were determined to be higher than other fatty acids, were also found to be higher in many legume forage plant seeds such as I Medicago i , I Lotus corniculatus i , I Trigonella foenum-graecum i , I Trifolium i spp., I Onobrychis fallax i , and I Vicia i spp. [[7], [17]]. Fatty acids and mineral elements also play an important role in animal feeding. [Extracted from the article]

This study characterized the effect of green manures (February orchid, hairy vetch, rattail fescue and a no-green-manure control) and the termination method (flail or disk) on nutrient contents, enzyme activities, microbial biomass, microbial community structure of rhizosphere soil and vegetative growth of walnut tree. All three selected green manures significantly enhanced the water content, organic C, total N and available P. The rattail fescue significantly decreased the mineral N. Total organic C, total N, mineral N and available P were significantly greater under flail than under disk. Hairy vetch and February orchid significantly improved levels of soil β-glucosidase, N-acetyl-glucosaminidase and acid phosphatase activity, whereas rattail fescue improved only β-glucosidase activity. All of the green manures significantly decreased phenoloxidase activity. β-glucosidase, N-acetyl-glucosaminidase and acid phosphatase activities were significantly greater under flail relative to disk. The termination method had no significant effect on phenoloxidase activity. The different types of green manures and termination methods significantly altered the soil microbial biomass and microbial community structure. The green-manure treatments were characterized by a significantly greater abundance of Gram-positive (Gram +) bacteria, total bacteria and saprophytic fungi compared to the control. Hairy vetch significantly decreased the abundance of arbuscular mycorrhizal fungi (AMF) while February orchid and rattail fescue increased their abundance compared to the no-green-manure treatment. The abundance rates of Gram+ bacteria, actinomycetes, saprophytic fungi and AMF were significantly greater in soils under flail than under disk. In terms of vegetative growth of walnut tree, hairy vetch showed the greatest positive effects. The growth of walnut tree was significantly greater under flail relative to disk. Our results indicate that green-manure application benefits the rhizosphere soil micro-ecology, rhizosphere soil nutrient contents and tree growth. Overall, the hairy vetch and flail combined treatment is recommended for walnut orchards in northern China. [ABSTRACT FROM AUTHOR]

Rice straw (RS) was incorporated into paddy soil together with leguminous green manure (e.g., Chinese milk vetch, Astragalus sinicus L., MV) in a mesocosm-scale experiment and the enzyme activity and composition of main microbial groups were measured. Mixing MV and RS caused a synergistic release of residual C and N, leading to a low C/N ratio at the middle and late decomposition stages of the mixture and shortening the time to complete decomposition. Furthermore, the highest abundances of Gram-negative (G−) bacteria and fungi and the highest activities of α- and β-glucosidase, β-cellobiosidase, β-xylosidase, N-acetyl-glucosaminidase, and acid phosphomonoesterase were observed in the residue mixture, especially at the middle and late stages of the experiment. The residue decomposition rate was positively correlated with residual N and mineral N concentrations. Most hydrolases and both oxidase (phenol oxidase and peroxidase) activities, and G− bacterial (especially 18:1 ω5c, Photobacterium) abundance explained the decomposition of mixing residues. In conclusion, co-incorporation of MV and RS could stimulate their decomposition by retaining a relatively low C/N ratio, enhancing G− bacterial abundance and hydrolase activities. Introducing leguminous green manures in paddy fields may be an effective way to accelerate the decomposition of rice straw. [ABSTRACT FROM AUTHOR]

In Egypt, Rhizoctonia solani is an economically important fungal pathogen on many crops such as common bean causing serious yield losses. Biofumigation with Indian mustard (Brassica juncea), as a potential alternative to the restricted fumigant methyl bromide, is gaining attention in sustainable vegetable production. In this study, laboratory and greenhouse experiments were conducted to evaluate the biofumigation effect of B. juncea, used as dry plants, seed meal, seed powder, methanol extract, and fresh plants (at the vegetative and flowering stages), against R. solani. Results showed that hexane defatted seed meal was the most efficient one, followed by the seed powder, fresh plants at the flowering stage then fresh plants at the vegetative stage. The fungal inhibition rate was 61.5, 50.2, 49.9, and 47.7%, respectively. While the dry plants at both flowering and vegetative stage recorded the lowest suppressive effect (44.3 and 39.1%, respectively). The findings open up the possibility of using the B. juncea in managing the root rot fungus, not only as a common green manure but also as a defatted seed meal. [ABSTRACT FROM AUTHOR]

Many factors are driving interest in improving soil health in potato production systems in the U.S. Pacific Northwest and beyond, including the need for enhanced sustainability and economic viability, and consumer preferences. Potato production poses a particular challenge in terms of soil health due to intensive tillage, minimal residue left on fields, short rotations, and the importance of managing soilborne pathogens. This review discusses existing soil health assessment methods and their relevance for the region and summarizes results of studies conducted in the Pacific Northwest and beyond, examining practices aimed at improving soil health and their effects on soil health, soilborne pathogens, yield and quality of potatoes, and net returns in potato production systems. These practices include reducing tillage; adjusting crop rotation length and species composition; reducing fumigation; and using cover crops, green manures, and organic amendments. [ABSTRACT FROM AUTHOR]

Among technologies of saline–alkali land management and improvement, some can be applied to different regions and causes, and play the role of generic technology. In this paper, by using the patent Derwent Innovation Index, we firstly retrieve the relevant patents, then through cleaning the patent data, build a patent citation network. Finally, we use technology co-occurrence strength, out centrality, betweenness centrality, SPLC path analysis, the number of patent families as well the number of valid countries or territories designated by the patent for identification, from fundamentality, externality and benefit of generic technology characteristics. The conclusion is that fertilizer, organic fertilizer and green manure, microbial fermentation technology, soil tillage and working technology, irrigation and drainage systems and the saline, the saline–alkali substance cleaning technology, planting salt-tolerant plants are generic technologies for saline–alkali land management and improvement. [ABSTRACT FROM AUTHOR]

The deep-placement of nutrient-rich organic amendments in poorly-structured subsoils can improve subsoil structure and increase grain yields, but its widespread adoption by farmers is limited by the availability and cost of animal manures, the current choice of amendment. Three glasshouse experiments investigated the effectiveness of dried field pea (Pisum sativum L.) shoots (green chop), as green manure, on wheat growth in three subsoils with contrasting soil chemical and physical properties. The growth of wheat plants was greatly suppressed when the green chop was placed in Sodosol and Chromosol subsoils. In contrast, there was a twofold increase in shoot biomass in response to the addition of green chop to Vertosol. Three allelopathic compounds, pisatin, anhydropisatin, and maackian, were identified at higher concentrations in the extracts of remaining green chop residues in the Sodosol and Chromosol, compared to the Vertosol, directly supporting phytotoxicity as the cause of observed inhibitory effects of green chop in these soils. The persistence of the phytotoxicity in the Sodosol might be attributed to its poor aeration caused by poor structure or compaction. Nevertheless, pre-incubation led to microbial decomposition of the allelochemicals in the Sodosol, though at a much slower rate than in the Vertosol. Further studies are needed to determine the time period required for the disappearance of the phytotoxic effects in soils with different physico-chemical properties. [ABSTRACT FROM AUTHOR]

Sesbania is a genus in the family Leguminosae that has been widely used by people in tropical and subtropical regions, especially in Southeast Asia. Information about Sesbania uses and their characteristics such as chemical compounds were obtained from 233 papers, reports and books. We found evidence for 22 Sesbania species being used. They were used for human food (10 species), animal food (9), poisons (1), medicines (10), environments (8), materials (7), fuel (2) and social purposes (1). Sesbania grandiflora and S. sesban were used more than the other species. Sesbania grandiflora was the only species with uses in all categories. Sesbania sesban was used in six categories. Sesbania grandiflora had the highest number of use records in almost all categories, except for fuel in which S. sesban had more records. The aerial parts, especially the soft, young parts were consumed by both humans and animals. Some Sesbania species contained high amounts of proteins (41% of protein in S. javanica), vitamin C (145 mg/100 g in S. grandiflora) and high amounts of calcium (666 mg/100 g in S. grandiflora). Sesbania species have been used to treat 20 subcategories of human disorders, and also as veterinary medicines. Sesbania possessed 1-O-β-D-glucopyranosyl-2-hydroxy-N-pentadecanamide, 2-hydroxy-N-decanamide, betulinic acid, isovestitol, medicarpin, oleanolic acid 3-β-D-glucuronide, pinitol, saponin, sativan, sesbanimide, stigmasterol and triterpene acid 3-O-α-L-rhamnopyranoside for which pharmacological properties had been tested. Sesbania also has cardioprotective, antidiabetic, antiurolithiatic, hypolipidemic, anticancer, analgesic, and anti-inflammatory effects. Sixteen microorganisms were found to be inhibited by Sesbania. Sesbania species are well-known for their use as green manures and seven species were recorded for this purpose. Sesbania also have properties that make them useful for pollution control. Regarding material uses, five Sesbania species were used for their fibers and Sesbania bispinosa was used in the production of fabrics. Besides the uses, Sesbania species also have other economic importance as weeds, pest host, and host for an economic plant. Eight species of Sesbania appear to have negative effects as weeds and pest-host and one species (Sesbania grandiflora) was the host for sandalwood. There was evidence that Sesbania could inhibit growth of animals and plants. Moreover, Sesbania seeds in too large doses are lethal to some animals. According to the vast advantages, the knowledge of Sesbania uses, including the safe dosages, should be passed on for the welfare of humans. [ABSTRACT FROM AUTHOR]

Background and aims: Green manuring can suppress crop diseases and change soil microbial communities, but the functional significances of changes in soil microbial communities are unclear. Methods: Effects of Indian mustard (Brassica juncea), wild rocket (Diplotaxis tenuifolia) and wheat (Triticum aestivum) green manures on cucumber (Cucumis sativus L.) Fusarium wilt disease caused by Fusarium oxysporum f.sp. cucumerinum (FOC) were evaluated. Cucumber rhizosphere microbial communities were analyzed by real-time PCR and high-throughput amplicon sequencing. Furthermore, feedback effects of rhizosphere biota on cucumber resistance to FOC were assessed. Results: All green manures promoted cucumber growth and changed rhizosphere bacterial community composition. Indian mustard and wild rocket green manures decreased Fusarium wilt disease severity and rhizosphere FOC abundance, increased bacterial diversity and abundance of potential plant-beneficial microorganisms. Rhizosphere biota from cucumber cultivated with Indian mustard and wild rocket (but not with wheat) green manures suppressed Fusarium wilt disease and enhanced expression of defense-related genes in cucumber seedling roots. Pseudomonas spp. strains isolated from cucumber rhizosphere cultivated with Indian mustard and wild rocket green manures suppressed cucumber Fusarium wilt disease. Conclusions: Changes in cucumber rhizosphere microbial communities induced by Indian mustard and wild rocket suppressed Fusarium wilt disease by priming for defense in plants. [ABSTRACT FROM AUTHOR]

Background: Different bulking agents are used in the compost of dewatered sludge (DWS). The aim of this study has been using of indigenous bulking agents (IBAs) in the enhancing of the DWS class of municipal wastewater from class B to class A and complementary stabilization of it for production of green manure in Sari city, Iran. Methods: Three IBAs including the Saccharum Wastes (SW), Citrus Purning Wastes (CPW) and Phragmites Australis (PA) from eight IBAs were selected to be compared with the sawdust (SD) that was as a control bulking agent. Five turned windrow piles were constructed on a full scale and on base of optimal C/N equal 25.All experiments were performed on the base of the standard methods on initial mix and final compost. Results: Among five windrow piles, P5 was been the best pile with a weighting ratio of DWS to IBAs (DWS: SW: CPW: PA) equal 1: 0.2: 0.24: 0.28. Pile P1 with weighting ratio DWS: SW equal 1: 0.6, Pile P3 with weighting ratio DWS: PA equal 1: 0.84, Pile P2 with weighting ratio DWS: CPW equal 1: 0.73 and Pile P4 with weighting ratio DWS: SD equal 1: 0.57 were placed in the next rounds. The results showed that the class of DWS enhanced to Class A for about 80 to 97 days and complementary stabilization of DWS by IBAs was done well and produced green manure in term of organic matter, potassium, germination index, PH, C/N and electrical conductivity had reached to the Grade 1 of Iran's manure 10716 standard and in term of phosphorus and moisture had reached to the Grade 2 of this standard. Also heavy metals were below the maximum permissible of standards. Conclusion: Using of IBAs, had a higher efficiency than the control bulking agent (sawdust) in enhancing sludge class and its stabilization, so that using of them in combination (mix of IBAs) had the highest efficiency and respectively, Saccharum Wastes (SW), Phragmites Australis (PA), Citrus pruning wastes (CPW) were placed in the next round, and sawdust was placed after them. By adding suitable IBAS, with an optimal ratio in turned windrow method, the class of DWS of sari WWTP enhanced to Class A and complementary stabilization of DWS has been well done and the produced green manure has been reached to agricultural standards and can be safely used in agriculture. [ABSTRACT FROM AUTHOR]

Aims: The objective was to estimate the fixation of atmospheric nitrogen (Ndfa) by legume (Gliricidia sepium) trees for the benefit of cocoa (Theobroma cacao) trees in agroforestry systems.Methods: Four sites where cocoa and gliricidia were intercropped and one site where gliricidia, cocoa, and orange trees were grown as separate stands were selected in Ghana. Ndfa in gliricidia and cocoa leaves (from all sites) and in shoot axes (in one site only) was assessed by the 15N natural abundance technique. Cocoa trees distant (> 10 m) from the closest gliricidia were used as reference plants.Results: With few exceptions, leaves of gliricidia and cocoa trees growing in proximity had similar δ15N, whereas the foliar δ15N value of gliricidia was lower than that of distant cocoa trees. The Ndfa in gliricidia leaves ranged from 22 to 50% of total leaf N and was 48% in the shoot axis. Root nodules, found only after the wet season, always showed the inner red color indicating effective N2 fixation and the occurrence of Rhizobium tropici and Rhizobium etli. The annually produced shoots of gliricidia, theoretically suitable to become green manure after pruning, contained 31.4 to 38.0 kg N ha−1 derived from the atmosphere.Conclusions: Gliricidia sepium trees are able to take advantage of the association with rhizobial symbionts to fulfill, at least in part, the N needs of their rapidly growing shoots. In mixed-stand agroforestry systems, with intercropped gliricidia and cocoa trees, the amount of N derived from the atmosphere that could enter the soil if the pruned shoots of gliricidia trees are used as green manure could diminish the need for N fertilizers for cocoa trees. [ABSTRACT FROM AUTHOR]

Aims: We investigated the effect of the co-composting of Arachis pintoi (AP) as green manure with different sources of rock phosphate on maize growth and soil properties.Methods: Composts were prepared combining AP and different rock phosphates (simple superphosphate, apatite rock phosphate, reactive rock phosphate and thermophosphate), alone or in combination with AP. The incorporation of AP and natural phosphate was conducted in a greenhouse, and we investigated its effects on plant total dry matter, phosphorus absorption, microbial biomass carbon and phosphorus, total organic carbon, soil basal respiration, enzymatic activities (acid phosphatase, alkaline phosphatase and urease) and the soil microbial structure community.Results: The application of natural thermophosphate phosphates with AP is an efficient management strategy for maize cultivation, with increases of more than 124% in maize dry matter, more than 300% in P uptake and 62% in soil microbial biomass carbon.Conclusions: The use of Arachis pintoi as green manure, combined with natural phosphate sources, represents an alternative fertilisation approach for maize cultivated on Entisols, enhancing the bioavailability of P from natural rock phosphate. It is a sustainable and financially attractive option to ensure the environmental integrity of cultivation, food and soil security. [ABSTRACT FROM AUTHOR]

Aims: To identify the rhizobia nodulating Astragalus sinicus in the acid soils at Xinyang, China and to estimate the effects of fertilization strategies on the rhizobial community.Methods: Soil samples were collected from treatments submitted to different fertilization strategies (chemical fertilizers, A. sinicus green manure, various input levels). Nodules obtained from the A. sinicus trapping plants grown in the soil samples were used for rhizobial isolation. The isolates were grouped into PCR-RFLP genotypes based on analyses of 16S rRNA gene and IGS, and representatives for each genotype were further subjected to phylogenetic analyses of housekeeping genes (16S rRNA gene, atpD, glnII, and rpoB), as well as symbiotic genes (nodC and nifH). Soil physicochemical characteristics were also estimated and redundancy analysis was performed to examine the relations between soil features and distribution of rhizobial genotypes across different fertilization treatments.Results: A total of 257 rhizobial isolates were obtained and discriminated into 12 IGS types in a single 16S rRNA type by RFLP analyses. Further 16S rRNA gene sequence-based phylogeny and multilocus sequence analysis (MLSA) distinguished a minor group (10 strains, 4 IGS types) affiliated to Mesorhizobium huakuii and a main group (247 strains, 8 IGS types) to Mesorhizobium jarvisii, for which a novel symbiovar, sv. astragali, was described. The long-term input of A. sinicus green manure increased rhizobial diversity and modified rhizobial community structures, via the increase of organic matter and decrease of soil pH, available phosphate, available potassium, and total salt.Conclusions: M. jarvisii sv. nov. astragali was the predominant microsymbiont of A. sinicus in the tested acidic soils. The long-term input of green manure modified the soil features, enhancing the genetic diversity of rhizobia associated with A. sinicus and alternating the rhizobial community structure. [ABSTRACT FROM AUTHOR]

In the worldwide search for new strategies in sustainable weed management, the use of allelopathic plants incorporated into the soil as green manure can help control weeds by releasing allelochemicals into the environment. In previous experiments, Eucalyptus globulus leaves incorporated into the soil as green manure were shown to have a notable potential for weed control. But, ‘what was exactly happening at chemical level?’ and ‘which were the compounds potentially responsible for the phytotoxic effects observed during those greenhouse assays?’ In the present study, in-vitro phytotoxicity bioassays and chemical analysis of eucalyptus leaves were carried out in order to explore the relationship between the temporal phytotoxic effects and the dynamics of chemical composition. For that, eucalyptus leaves were removed from soil at different sampling times during 30 days and analyzed for phenolic and volatile organic compounds (VOCs) by HPLC and HS-SPME/GC-MS, respectively. The phytotoxic potential of the aqueous extract and the volatile fraction was tested on the germination and early growth of Lactuca sativa. Eucalyptus leaves incorporated into the soil as green manure showed a continuous release of different phenolic and volatile compounds during a 30-day period of decomposition. Both fractions had phytotoxic effects during the time assayed; however, the target process of phytotoxicity was different: phenolic compounds being the factor causing germination inhibition and VOCs responsible for growth reduction. The dynamics of release of this cocktail of allelochemicals into the soil environment may be the responsible for the phytotoxicity observed in our previous works. [ABSTRACT FROM AUTHOR]

Background and aims: Crucifers grown as cover crops are known to reduce sulphate leaching (S catch-crop service) and release large amounts of mineral sulphate for the subsequent cash crop once incorporated into the soil (S green-manure service). Crucifer-legume cover crop mixtures are effective to obtain high nitrogen related services, but few data exist on their performances for S-related services. Our study aimed to assess performances of a wide variety of bispecific crucifer-legume mixtures designed to provide soil S catch-crop and S green-manure services.Methods: A two-year field experiment was conducted at two sites near Toulouse, France (silt clay loam soil) and Orléans, France (sandy loam soil) in which cultivars from eight crucifer species and nine legume species were tested as sole and bispecific cover crops.Results: Crucifer-legume mixtures and crucifer sole cover crops provided the same level of S catch-crop service (12 kg S ha−1), significantly higher than that of legume sole cover crops (4 kg S ha−1). Similarly, crucifer-legume mixtures provided almost the same level of S green-manure service (5.5 kg S ha−1) as crucifer sole cover crops (6.5 kg S ha−1).Conclusion: Our results demonstrate the compatibility and complementarity of certain crucifer and legume species when grown together to provide S and N catch-crop and green-manure services. For a same cover crop species no strong cultivar effect has been highlighted in our growing conditions. [ABSTRACT FROM AUTHOR]

Background and aims: We investigated whether the incorporation of intercropped white clover as a split-dose fertiliser improves N retention of the plant-soil system in leek production.Methods: White clover and leek were grown in pots where clover was stepwise incorporated into soil as fertiliser. Half of the clover was incorporated before leek transplantation (LT), the other half was incorporated 26 (S1) or 41 (S2) days after LT, compared with full incorporation of all clover (F) before LT. 15N injection and leaching studies were performed to investigate interspecific competition and the effects of precipitation on soil N availability.Results: Stepwise incorporations increased or had no effect on leek growth, despite competition for N between white clover and leek. Compared to F, leek grown with stepwise incorporations had similar and lower N accumulation before the second incorporation, but N was higher at the end of the experiment. N2 fixation by white clover increased the total N input into soil and matched N availability with leek N demand and growth rate. Loss of inorganic N by leaching was lowest in S2 and highest in F.Conclusions: Stepwise incorporations of white clover improved N retention in the plant-soil system and could be used to increase leek yield. [ABSTRACT FROM AUTHOR]

The use of green manures in agriculture can provide nutrients, affect soil microbial communities, and be a more sustainable management practice. The activities of soil microbes can effect crop growth, but the extent of this effect on yield remains unclear. We investigated soil bacterial communities and soil properties under four different green manure fertilization regimes ( Vicia villosa, common vetch, milk vetch, and radish) and determined the effects of these regimes on maize growth. Milk vetch showed the greatest potential for improving crop productivity and increased maize yield by 31.3 %. This change might be related to changes in soil microbes and soil properties. The entire soil bacterial community and physicochemical properties differed significantly among treatments, and there were significant correlations between soil bacteria, soil properties, and maize yield. In particular, abundance of the phyla Acidobacteria and Verrucomicrobia was positively correlated with maize yield, while Proteobacteria and Chloroflexi were negatively correlated with yield. These data suggest that the variation of maize yield was related to differences in soil bacteria. The results also indicate that soil pH, alkali solution nitrogen, and available potassium were the key environmental factors shaping soil bacterial communities and determining maize yields. Both soil properties and soil microbes might be useful as indicators of soil quality and potential crop yield. [ABSTRACT FROM AUTHOR]

Potato cyst nematodes (PCN), Globodera spp., are major pests of potato worldwide. In this study, the toxicity of an aqueous extract (1 g/ml) of fresh leaves of brassica species (savoy cabbage, cauliflower, broccoli, red cabbage, turnip, white mustard and edible radish) was tested on G. rostochiensis encysted eggs and infective, second-stage juveniles (J2) in vitro. Soil infested with cysts (Pi 20 eggs/g soil) was either fumigated with metham sodium and/or biofumigated with 2 % green manure of brassica and wheat under glasshouse conditions. More than 99 % of the J2 were paralysed after 24 h and <1 % of J2 hatched from encysted eggs during a 6-week exposure to brassica extracts. Nematode reproduction on the susceptible potato cv. Marfona was reduced by green manure amendments, the numbers of new cysts was reduced by between 60 % in radish- and 33 % in cauliflower-treated soil. The reproduction rate of G. rostochiensis was reduced to less than 1, and final populations of eggs and J2/g soil were reduced by between 73 % (white mustard) and 92 % (edible radish). Likewise, green manure of wheat and metham sodium fumigation decreased potato cyst nematode reproduction rates to below one, new cysts by 50 and 42 %, and final eggs/g soil by 81 and 88 %, respectively. In infested soil, total fresh weight of aerial parts and roots of potato was decreased by 64 %, while total weight of plants was increased between 21 and 74 % in brassica amended soil, and 56 and 76 % in wheat and metham sodium-treated soil, respectively. [ABSTRACT FROM AUTHOR]

This paper examines the impact of animal manure on δN and δC values in a legume, Celtic Black broad bean ( Vicia faba). In a field experiment, V. faba was cultivated in plots treated with farmyard manure and pure sheep manure. The results indicate that highly intensive manuring can increase δN values in beans, stems, leaves and pods. In comparison, manuring had a relatively small impact on δC values. In terms of palaeodietary reconstructions, the high δN values in very intensively manured beans (+3 ‰) are equivalent to the trophic-level effect. Based on the experimental results, it is suggested that high δN values in archaeobotanical remains of V. faba may be attributable to small-scale cultivation with intensive manuring. [ABSTRACT FROM AUTHOR]

The objective of the present study is to investigate the effects of irrigation water salinity, cow manure levels and different planting methods on saffron quality compounds including crocin (coloring strength), picrocrocin (bitterness) and safranal (aromatic strength). A split-split plot arrangement was conducted in complete randomized block design with irrigation water salinity levels (0.45 (fresh water, S¹), 1.0 (S2), 2.0 (S3) and 3.0 (S4) dS m-1) as the main plot, cow manure levels (30 (F¹) and 60 (F²) Mg ha-1) as the sub plot and planting method (basin (P¹) and in-furrow (P²)) as the sub-sub plot in three replications. Results showed that the saffron coloring strength, bitterness and aromatic strength in higher salinity level decreased by 9, 13 and 18% in comparison with the lowest salinity level, respectively. However, saffron (stile/stigmas) yield declined significantly as about 42% by increasing water salinity to highest level. The saffron crocin and picrocrocin concentration for the in-furrow planting method were significantly higher than the basin planting method by about 4 and 8%, respectively. Higher application rate of cow manure (60 Mg ha-1) did not promote the saffron quality compounds. Furthermore, planting methods showed no significant effect on saffron aromatic strength. Correlation analysis indicated that saffron quality compounds showed negative relationship with leaf calcium, sodium and chloride and positive relationship with leaf phosphorus, nitrogen and potassium at 0.01 and 0.05 significant levels, Furthermore, a positive correlation between crocin and picrocrocin and saffron yield components (leaf dry matter, corm, flower and saffron yields) was observed; however, there was no significant correlation between safranal and yield components. Generally, the saffron quality compounds variations were concurrent with the saffron quantity variations. [ABSTRACT FROM AUTHOR]

Returning crop residues to soil is an effective approach for sustaining organic matter concentrations and increasing nutrient availability in soils. A 2-year micro-plot field experiment was conducted in dryland to determine the green manure, straw, and fertilizer nitrogen (N)-15 uptake by wheat, their residual N in soil and losses; the effect of straw application on the fate of N from green manure and vice versa was also determined, as well as the effect of crop residue additions on the fate of fertilizer N. All the micro-plots were treated with the same amount of N-labeled or unlabeled fertilizer. The green manure N uptake by wheat, residual N, and N loss were 22.4, 51.7, and 25.9 % of the total added green manure N over the 2-year experiment. Straw addition significantly decreased the green manure residual soil N but increased the cumulative losses. The straw N taken up by wheat, residual N in soil, and N loss were 8.3, 31.0, and 60.7 %, respectively. Green manure addition significantly decreased the straw N taken up by wheat, increased the residual soil N, and reduced the N loss. Furthermore, the fertilizer N taken up by wheat, residual N in soil, and N loss were 32.4, 32.3, and 35.2 %, respectively. Crop residue additions significantly increased the uptake of fertilizer N by wheat in the second year. The application of inorganic N fertilizer in combination with appropriate crop residues may be an effective approach to improve the long-term fertilizer N use efficiency, soil quality, and crop yield in wheat-summer fallow rotation systems in dryland. [ABSTRACT FROM AUTHOR]

Conventional agriculture strongly alters soil quality due to industrial practices that often have negative effects on soil life. Alternative systems such as conservation agriculture and organic farming could restore better conditions for soil organisms. Improving soil life should in turn improve soil quality and farming sustainability. Here, we have compared for the first time the long-term effects of conservation agriculture, organic farming, and conventional agriculture on major soil organisms such as microbes, nematofauna, and macrofauna. We have also analyzed functional groups. Soils were sampled at the 14-year-old experimental site of La Cage, near Versailles, France. The microbial community was analyzed using molecular biology techniques. Nematofauna and macrofauna were analyzed and classified into functional groups. Our results show that both conservation and organic systems increased the abundance and biomass of all soil organisms, except predaceous nematodes. For example, macrofauna increased from 100 to 2,500 %, nematodes from 100 to 700 %, and microorganisms from 30 to 70 %. Conservation agriculture showed a higher overall improvement than organic farming. Conservation agriculture increased the number of many organisms such as bacteria, fungi, anecic earthworms, and phytophagous and rhizophagous arthropods. Organic farming improved mainly the bacterial pathway of the soil food web and endogeic and anecic earthworms. Overall, our study shows that long-term, no-tillage, and cover crops are better for soil biota than periodic legume green manures, pesticides, and mineral fertilizers. [ABSTRACT FROM AUTHOR]

More efficient use of green manure-derived nitrogen (N) may improve crop yields and reduce environmental impacts in stockless organic arable farming. In this 3-month incubation study, we tested a new strategy where green manure leys are harvested and preserved until the following spring either as compost mixed with straw or as silage of harvested ley biomass. Grass-clover compost or silage was soil-incorporated by either simulated ploughing (green manure placed at 15 cm depth) or harrowing (green manure mixed into the upper 5-cm soil horizon) in order to assess treatment effects on net release of plant-available N, nitrous oxide (NO) fluxes and soil respiration. Grass-clover silage provided the highest net N release with similar results for the two incorporation methods. Up to one third of the total N content in silage became plant-available during the 3 months. In contrast, no net N release was observed for the composted grass-clover and straw mixture. In fact, soil incorporation of compost by harrowing caused temporal immobilization of soil mineral N. Silage incorporated by ploughing gave rise to the largest NO effluxes with silage-induced emissions corresponding to 0.3 % of applied total N. Possibly NO production via denitrification was stimulated by oxygen-limited conditions near the decomposing silage. In contrast, compost incorporated by harrowing caused net NO uptake, presumably an effect of reduced mineral N availability in this treatment. Overall, our study revealed that ensiled grass-clover was the best fertilizer product and that the method chosen for incorporation of green manure is likely to influence NO emissions. [ABSTRACT FROM AUTHOR]

The abundance and activity of the soil microflora were studied in a field experiment with the use of green manure crops to assess the impact of reclamation measures on the biological activity of soils of the solonetz complex. The number of microorganisms in the plow soil horizon increased in the background of the green fallows as compared to the black ones. Coefficients of mineralization, immobilization, and transformation of organic compounds were calculated for different variants of the soil treatment. The value of the mineralization coefficient indicates the intense decomposition of the green manure that entered the soil. In the first year, peas were actively decomposed, while oats, in the second year (aftereffect). The activity of the soil enzymes (invertase, urease, and catalase) was determined. A close relationship between the catalase activity and the intensity of the microbiological processes in the soils was revealed. [ABSTRACT FROM AUTHOR]

Soilborne potato diseases are persistent problems in potato production. Use of disease-suppressive rotation crops, such as Brassica spp. (mustards, rapeseed) and sudangrass, has shown potential for management of soilborne diseases and enhanced yield in various crop production systems. However, how to best implement these crops into productive potato cropping systems has not yet been determined. In this research, potential disease-suppressive crops were evaluated under four different types of production management (as a cover crop, green manure, harvested crop-residue incorporated, and harvested crop-residue not incorporated) in potato rotation field trials, and their effects on disease, yield, and economic viability determined. Mustard blend, sudangrass, and rapeseed rotations reduced the tuber disease black scurf (by 16-27 %) and increased yield (by 6-11 %) relative to a barley rotation control, but only mustard blend consistently reduced common scab (by 11 %). All rotation crops managed as green manures produced lower disease (by 15-26 %) and higher yields (by 6-13 %) than other management practices. Overall, the combination of mustard blend managed as a green manure was most effective, reducing scurf by 54 % and increasing yield by 25 % relative to a soybean cover crop. The use of mustard or rapeseed as a harvested crop with incorporation provided the best economic return, increasing net income by more than $860/ha relative to the standard barley rotation, but mustard blend grown as a green manure or non-incorporated harvest crop also substantially increased net income ($600 to $780/ha). [ABSTRACT FROM AUTHOR]

Biomass of legumes grown as catch crops improves soil properties and thus soil conditions for following crops. The aim of this study was to evaluate the effect of field pea (Pisum sativum L.) grown as a catch crop and used for green manure on soil properties and yielding of spring barley (Hordeum vulgare L.). Field experiments were conducted in 2008-2011 in the randomized block design with four replications, in typical black earth. The experimental factor was the time and way of catch crop incorporation: in autumn-with plowing (1); in the spring-with disking (2); control-without a catch crop (3). The soil with the catch crop contained significantly higher mineral nitrogen in the topsoil during tillering of barley than the control. Catch crop caused significant decrease in soil moisture and increase in penetration resistance in the topsoil in autumn. No significant effect of the catch crop on soil moisture during spring barley growing season in the following spring was obtained. Catch crop plowing in autumn caused significant decrease in soil penetration resistance in the 20-30 cm layer in early spring. Catch crop biomass plowed positively affected the number of spikes in sequential spring barley. Leaving pea as mulch for winter caused significant increase in 1000 grain weight compared to the control. Field pea grown as a catch crop for green manure can be recommended for increasing mineral nitrogen concentration and the soil biological activity in the topsoil. However, its influence on spring barley yield in fertile soils is low. [ABSTRACT FROM AUTHOR]

The effects of different types of green manure ( Trifolium pratense L., Dactylis glomerata L., and Secale cereale L.) and the time of its input into the soil (autumn and spring) on the contents of humus and labile humus substances in a soddy-podzolic soil and the relationship between the formation of humus and the chemical composition of the applied biomass were studied. Green manure had a positive effect on the accumulation of humus in the soil. When the plants were plowed into the soil in the fall, the amount of humus formed in the soil in the first year was 0.1% higher in comparison with the spring application of green manure. The most active synthesis of new humus substances took place upon the following properties of the plant biomass: C: N = 15-25, the cellulose content of 20-28%, and the lignin content of 14-17%. The highest amount of labile humus substances was formed during the decomposition of the biomass with the C: N ratio above 20, the cellulose content of 19-20%, and the lignin content of 14-16%. [ABSTRACT FROM AUTHOR]

Harvesting alfalfa damages crowns and increases the opportunity for entry of pathogens. Incorporation of green manures into soil increases population density of streptomycetes with broad pathogen antagonist activity. This study aimed to measure the impact of wheel traffic on forage yield and plant health and the effect of green manures to reduce disease. Buckwheat and sorghum-sundangrass were incorporated into soil 3 weeks before seeding alfalfa. Total bacteria, streptomycete, and pathogen antagonist densities were measured prior to planting green manures and alfalfa. Wheel traffic was applied 2 days after each forage harvest. Wheel traffic reduced forage yield 12 % to 17 % depending on year and location, significantly reduced plant counts, and increased crown rot compared to the no traffic control. Cultivar had a significant effect on yield, plant counts, and crown rot. Streptomycete density and pathogen antagonists increased when fall-sown green manure crops were incorporated in spring. Forage yields were significantly higher in plots with greater antagonist density when traffic was applied. Green manure treatments did not affect plant counts or crown rot. Mechanical wheel traffic reduces forage yield and increases disease. Green manure crops may provide benefits in alfalfa production systems by increasing pathogen antagonists. [ABSTRACT FROM AUTHOR]

This study focuses on the effects of long-term rice rotated with milk vetch being as green manure on the composition of bacteria in rice roots. The endophytic bacterial communities in rice roots of the rice-rice-milk vetch (R-R-MV) and the rice-rice-winter fallow (R-R-WF) crop rotations with a 28-year research history were investigated using combined culture-dependent and culture-independent methods. It was found that the endophytic bacterial population in rice roots with the green manure was significantly higher than that of without it. There were 169 and 77 strains of endophytic bacteria that were isolated from rice roots of the R-R-MV and the R-R-WF, respectively. The 16S rRNA gene analysis shows that the 77 R-R-WF bacteria belong to 15 species of 14 genera while the other 169 R-R-MV bacteria belong to 21 species of 19 genera, in which Herbaspirillum and Cedecea were two mutually dominant populations and Burkholderia, Pseudomonas, Sphingomonas, and Pantoea accounted for large proportions of the endophytic bacteria in rice roots through R-R-MV rotation. The analysis of 16S rDNA clone libraries showed that the Shannon-Weaver diversity index of endophytic bacteria in R-R-MV approximates that in R-R-WF rotation, whereas the richness indexes of Chao 1 and ACE in R-R-MV rotation system were significantly higher than those in R-R-WF rotation. The diversity of endophytic bacteria was richer in R-R-MV. Both the culture-dependent and the culture-independent method revealed significant effect of long-term different tillage systems on the microbial community. [ABSTRACT FROM AUTHOR]

The combined seeding and cropping of non-leguminous and leguminous cover crops during the cold fallow season is recommended as an important agronomic practice to improve total biomass productivity and soil fertility in mono-rice ( Oryza sativa L.) cultivation system. However, application of plant residues as green manure can increase methane (CH) emission during rice cultivation and affect rice quality and productivity, but its effects are not well examined. In this field study, the mixture of barley ( Hordeum vulgare R.) and hairy vetch ( Vicia villosa R., hereafter, vetch) seeds with 75 % recommended dose (RD 140 kg ha) and 25 % RD (90 kg ha), respectively, were seeded after rice harvesting in late November, 2010, and harvested before rice transplanting in early June 2011. Total aboveground biomass was 36 Mg ha (fresh weight basis with 68 % moisture content), which was composed with 12 Mg ha of barley and 24 Mg ha of vetch. In order to determine the optimum recycling ratio of biomass application that can minimize CH emission without affecting rice productivity, different recycling ratios of 0, 25, 50, 75, and 100 % of the total harvested biomass were incorporated as green manure 1 week before rice transplanting in a typical temperate paddy soil. The same rates of chemical fertilizers (N-PO-KO = 90-45-58 kg ha) were applied in all treatments. Daily mean CH emission rates and total CH fluxes were significantly ( p < 0.05) increased with increasing application rates of cover crop biomass. Rice productivity also significantly ( p < 0.05) increased with biomass application, but the highest grain yield (53 % increase over the control) was observed for 25 % recycling. However, grain quality significantly ( p < 0.05) decreased with increasing cover crop application rates above 25 % recycling ratio, mainly due to extended vegetative growth periods of rice plants. Total CH flux per unit grain yield, an indicator used to simultaneously compare CH emission impact with rice production, was not statistically different between 25 % biomass recycling ratio and the control but significantly increased with increasing application rates. Conclusively, the biomass recycling ratio at 25 % of combined barley and vetch cover crops as green manure might be suitable to sustain rice productivity without increasing CH emission impact in mono-rice cultivation system. [ABSTRACT FROM AUTHOR]

Background and aims: Winter cover crop cultivation during the fallow season has been strongly recommended in mono-rice paddy soil to improve soil quality, but its impact in increasing the greenhouse gases (GHGs) emissions during rice cultivation when applied as green manure has not been extensively studied. In order to recommend a preferable cover crop which can increase soil productivity and suppress GHG emission impact in paddy soil, the effect of winter cover crop addition on rice yield and total global warming potential (GWP) was studied during rice cultivation. Methods: Two cover crops (Chinese milk vetch, Astragalus sinicus L., hereafter vetch, and rye, Secale cerealis) having different carbon/nitrogen (C/N) ratios were cultivated during the rice fallow season. The fresh above-ground biomasses of vetch [25 Mg fresh weight (FW) ha, moisture content (MC) 86.9 %, C/N ratio 14.8] and rye (29 Mg rye FW ha, MC 78.0 %, C/N ratio 64.3) were incorporated as green manure 1 week before rice transplanting (NPK + vetch, and NPK + rye). The NPK treatment was installed for comparison as the control. During the rice cultivation, methane (CH) and nitrous oxide (NO) gases were collected simultaneously once a week using the closed-chamber method, and carbon dioxide (CO) flux was estimated using the soil C balance analysis. Total GWP impact was calculated as CO equivalents by multiplying the seasonal CH, CO, and NO fluxes by 25, 1, and 298, respectively. Results: Methane mainly covered 79-81 % of the total GWP, followed by CO (14-17 %), but the NO contribution was very small (2-5 %) regardless of the treatment. Seasonal CH fluxes significantly increased to 61 and 122 % by vetch and rye additions, respectively, compared to that of the NPK treatment. Similarly, the estimated seasonal CO fluxes increased at about 197 and 266 % in the vetch and rye treatments, respectively, compared with the NPK control plots. Based on these results, the total GWP increased to 163 and 221 % with vetch and rye applications, respectively, over the control treatment. Rice productivity was significantly increased with the application of green manure due to nutrient supply; however, vetch was more effective. Total GWP per grain yield was similar with the vetch (low C/N ratio) and NPK treatments, but significantly increased with the rye (high C/N ratio) application, mainly due to its higher CH emission characteristic and lower rice productivity increase. Conclusions: A low C/N ratio cover crop, such as vetch, may be a more desirable green manure to reduce total GWP per grain yield and to improve rice productivity. [ABSTRACT FROM AUTHOR]

White lupin ( Lupinus albus L.) has been around since 300 B.C. and is recognized for its ability to grow on poor soils and application as green manure in addition to seed harvest. The seed has very high levels of protein (33-47 %) and oil (6-13 %). It also has many secondary metabolites that are potentially of nutraceutical value to animals and humans. Despite such a great potential, lupins role in modern agriculture began only in the twentieth century. Although a large collection of Lupinus germplasm accessions is available worldwide, rarely have they been genetically characterized. Additionally, scarce genomic resources in terms of recombinant populations and genome information have been generated for L. albus. With the advancement in association mapping methods, the natural populations have the potential to replace the recombinant populations in gene mapping and marker-trait associations. Therefore, we studied the genetic similarity, population structure and marker-trait association in a USDA germplasm collection for their current and future application in this crop improvement. A total of 122 PI (Plant Inventory) lines were screened with 18 AFLP primer pairs that generated 2,277 fragments. A subset of 892 polymorphic markers with MAF >0.05 (minor allele frequency) were used for association mapping. The cluster analysis failed to group accessions on the basis of their passport information, and a weak structure and low linkage disequilibrium (LD) were observed indicating the usefulness of the collection for association mapping. Moreover, we were also able to identify two markers (a p value of 1.53 × 10 and 2.3 × 10) that explained 22.69 and 20.5 % of seed weight variation determined using R. The implications of lack of geographic clustering, population structure, low LD and the ability of AFLP to map seed weight trait using association mapping and the usefulness of the PI collections in breeding programs are discussed. [ABSTRACT FROM AUTHOR]

Cultivation of green manure plants during the fallow season in rice paddy soil has been strongly recommended to improve soil properties. However, green manuring may impact greenhouse gas emission, methane (hereafter, CH) in particular, under the flooded rice cultivation and thus, application of chemical amendments being electron acceptors can be an effective mitigation strategy to reduce CH emissions in irrigated rice ( Oryza sativa L.) field amended with green manure. To investigate the effect of iron (Fe) slag silicate fertilizer (hereafter, silicate fertilizer), which was effective in reducing CH emission and increasing rice productivity, in green manure-amended paddy soil, the aboveground biomass of Chinese milk vetch (hereafter, vetch) was added at rates of 0, 10, 20, and 40 Mg (fresh weight) ha before the application of silicate fertilizer, which was added at rates of 0 and 2.3 Mg ha. Silicate fertilization reduced the seasonal CH flux by ca. 14.5% and increased rice yield by ca. 15.7% in the control (no vetch application) treatment. However, CH production was increased by silicate fertilization in vetch-treated soil particularly at the initial rice growing stage, which was probably due to the enhanced decomposition of added organic matters by the silicate liming effect. In conclusion, silicate fertilization is not effective in reducing CH production in green manure-amended rice paddy soils and its use should be properly controlled. [ABSTRACT FROM AUTHOR]

Nitrogen isotope abundance ( δN) of paddy rice ( Oryza sativa L.) grown for 110 days after transplanting (DAT) under field conditions with ammonium sulfate (AS with −0.4‰ as a synthetic fertilizer), pig manure compost (PMC with 15.3‰ as a livestock manure compost), and hairy vetch (HV with −0.5‰ as a green manure) was investigated to test the possible use of δN technique in discriminating organically grown from conventionally grown rice. At 15 DAT, the δN of whole rice decreased ( P < 0.05) in the order of 10.5‰ for PMC > 5.5‰ for control (without N input) > 4.0‰ for HV > 1.8‰ for AS. This difference seemed to reflect primarily the δN signal of N sources. Although differences in δN of rice grown with isotopically distinct N inputs (i.e. PMC vs. AS and PMC vs. HV) became smaller over time, the difference (2.8 and 3.0‰ difference at harvest on 110 DAT, respectively) was still significant ( P < 0.05). However, there was no distinguishable difference between AS and HV treatment after 42 DAT. Such effect of N inputs on δN of whole rice was also observed for root, shoot, and grain at harvest. Therefore, our study suggests that it is possible to distinguish rice grown with manure composts from that grown with synthetic fertilizers. However, if green manure of preceding N-fixing plants is used as the N source, δN of rice may not be a good surrogate of N sources. [ABSTRACT FROM AUTHOR]

The integration of multipurpose legumes into low-input tropical agricultural systems is needed because they are a nitrogen (N) input through symbiotic fixation. The drought-tolerant cover legume canavalia ( Canavalia brasiliensis) has been introduced for use either as forage or as a green manure into the crop-livestock system of the Nicaraguan hillsides. To evaluate its impact on the subsequent maize crop, an in-depth study on N dynamics in the soil-plant system was conducted. Microplots were installed in a 6-year old field experiment with maize-canavalia rotation. Direct and indirect N-labelling techniques were used to determine N uptake by maize from canavalia residues and canavalia-fed cows' manure compared to mineral fertilizer. Litter bags were used to determine the N release from canavalia residues. The incorporation of N from the amendment into different soil N pools (total N, mineral N, microbial biomass) was followed during the maize cropping season. Maize took up an average of 13.3 g N m, within which 1.0 g N m was from canavalia residues and 2.6 g N m was from mineral fertilizer, corresponding to an amendment N recovery of 12% and 32%, respectively. Recoveries in maize would probably be higher at a site with lower soil available N content. Most of the amendment N remained in the soil. Mineral N and microbial N were composed mainly of N derived from the soil. Combined total N recovery in maize and soil at harvest was highest for the canavalia residue treatment with 98% recovery, followed by the mineral fertilizer treatment with 83% recovery. Despite similar initial enrichment of soil microbial and mineral N pools, the indirect labelling technique failed to assess the N fertilizer value of mineral and organic amendments due to a high N mineralization from the soil organic matter. [ABSTRACT FROM AUTHOR]

Greater productivity under intercropping has been attributed to the complementary use of environmental resources. However, the rooting pattern of component species under intercropping, which is an important morphological feature considering the complementary uptake of nutrients, has been studied only rarely under field conditions because of inherent technical difficulties. We examined rooting patterns of three green manure species, both sole cropped and intercropped, using a newly developed multi-color staining technique. Species were chosen from different functional groups: sorghum ( Sorghum bicolor (L.) Moench.), a C4 grass; crotalaria ( Crotalaria juncea L.), a legume; and sunflower ( Helianthus annuus L.), a C3 dicot. We also investigated these species’ aboveground biomass and N uptake. Sorghum distributed roots deeper under intercropping than under sole cropping; it was the most important contributor to increased biomass under intercropping. Crotalaria had a deep rooting system under both sole cropping and intercropping. Sunflower, with a shallow rooting system, was suppressed extremely under intercropping, possibly because of water deficiency in late in the season. The rooting patterns of green manure species examined using multi-color staining were related closely to the aboveground performance of these species under intercropping. [ABSTRACT FROM AUTHOR]

Soil-incorporated plant materials have been associated with reduction in soilborne pathogens and diseases. Mechanisms of the biocidal actions are complex and not well understood. A glasshouse experiment, a non replicated field demonstration, and a field experiment were conducted to determine volatile compounds after incorporation of various plant species and their effect on pest control. Cabbage ( Brassica oleracea), canola ( Brassica rapa), kale ( Brassica oleracea var. acephala), lettuce ( Lactuca sativa var. valmaine), two mustard varieties -Caliente ( Brassica juncea) and Green wave ( Brassica juncea), two radish varieties - Oil seed ( Raphanus sativus var. oleiformis) and Cherriette ( Raphanus sativus), common rye ( Secale cereale), and sorghum Sudan grass ( Sorghum bicolor var. sudanese) were used in the glasshouse experiment. Caliente 199 mustard ( Brassica hirta) was planted in the field demonstration and white mustard ( Sinapis alba) was used in the field experiment. Fresh plant materials were chopped manually in the glasshouse experiment and mechanically in the field studies at the flowering stage before incorporation in natural field soils. In the glasshouse experiment, the equivalent biomass dry weight ranged from a minimum of 573 g m−2 for L. sativa var. valmaine to a maximum of 1851 g m−2 for S. bicolor var. sudanese. The average biomass was 792 g m−2 for B. hirta and 804 g m−2 for S. alba in the two field studies, respectively. The glasshouse experiment used a loamy sand field soil inoculated with a natural fine sandy loam soil that was known to contain high populations of Verticillium dahliae. Soils at both field sites belonged to the sandy loam series, and efforts were made to maintain sufficient soil moisture for plant growth. Although the interest was to determine all volatile compounds in general, only methyl sulfide and dimethyl disulfide were identified and subsequently quantified. Depending on plant species and time of sampling (one to seven days after soil incorporation), 2.7 to 346.4 μg g −1 plant dry weight for methyl sulfide and 0 to 283.2 μg g −1 plant dry weight for dimethyl disulfide were found in the glasshouse experiment. In general, high concentrations of dimethyl disulfide and methyl sulfide appeared to have reduced V. dahliae colony counts in bioassay potato stem saps in the glasshouse experiment. However, the correlation was weak ( R 2 = 0.31), but a relatively stronger correlation was obtained ( R 2 = 0.58) when excluding B. oleracea and B. rapa from the regression. Dimethyl disulfide and methyl sulfide were nearly non-detectable in the field demonstration, consequently no disease assessment was made. In the field experiment, a production of 5.2 μg g −1 plant dry weight for methyl sulfide and 1.2 μg g −1 dry weight for dimethyl disulfide was found two days after soil incorporation of S. alba. Compared to the untreated control, total Fusarium oxysporum counts in field soil were significantly lower 39 days after S. alba incorporation. However, no significant impact was found on total Pythium counts. Soil population of citrus nematode ( Tylenchulus semipenetrans) in the S. alba plots was significantly reduced to similar levels found in the untreated control 112 days after S. alba incorporation. Compared to the untreated control, soil density of non plant parasitic freeliving nematodes was higher 39 days after S. alba incorporation. The study demonstrated quantifiable production of methyl sulfide and dimethyl disulfide gases from a variety of plant species in glasshouse and natural field environments. Some beneficial effects against V. dahliae, F. oxysporum, and T. semipenetrans were observed. Additional studies are needed to further elucidate these complex chemical and biological interactions. [ABSTRACT FROM AUTHOR]

In low input (e.g. organic) farming systems where soil phosphorus (P) fertilisers such as superphosphate are not used, maintaining sufficient available soil P for plant growth can be a major challenge. The use of P accumulating cover crops may increase P availability for subsequent crops. We hypothesised that P release from organic residues of legumes (faba bean ( Vicia faba) and field peas ( Pisum sativum)) could supply adequate P to meet the needs of a subsequent crop in a low P soil. A pot experiment was conducted to determine the contribution of P by legume green manure to subsequent corn using 33P labelled legume residues and 32P labelled inorganic fertiliser (KH2PO4). The treatments included two rates of P application, (a) 10 kg P ha−1 as legume root and shoot residues or as inorganic fertiliser with and without a C source, and (b) 38 kg P ha−1as a combination of legume shoot and root residues or a combination of root and inorganic fertiliser and inorganic fertiliser alone. An absolute control (zero P) was also used. Shoot dry matter, P uptake and P source (residues or fertilisers) of total P in corn were measured at harvest. Faba bean and field pea residues alone or in combination with fertilisers contributed up to 10% and 5% of the total P uptake by corn respectively, compared with up to 54% by inorganic fertilisers. Incorporation of field pea and faba bean residues with P concentrations higher than those observed under field conditions, may not always lead to adequate net P release to supply the early growth phase of subsequent crops. [ABSTRACT FROM AUTHOR]

Three different green manures were added to the tea garden soils separately and incubated for 40 days. After, incubation, acetanilide herbicides alachlor and metolachlor were spiked into the soils, separately, followed by the isolation of bacteria in each soil at designed intervals. Several bacterial strains were isolated from the soils and identified as Bacillus silvestris, B. niacini, B. pseudomycoides, B. cereus, B. thuringiensis, B. simplex, B. megaterium, and two other Bacillus sp. (Met1 and Met2). Three unique strains with different morphologies were chosen for further investigation. They were B. megaterium, B. niacini, and B. silvestris. The isolated herbicide-degrading bacteria showed optimal performance among three incubation temperatures of 30°C and the best activity in the 10 to 50 μg/ml concentration of the herbicide. Each bacterial strain was able to degrade more than one kind of test herbicides. After incubation for 119 days, B. cereus showed the highest activity to degrade alachlor and propachlor, and B. thuringiensis to degrade metolachlor. [ABSTRACT FROM AUTHOR]

The Sesbania has been widely used as green manure to improve the productivity of several crops. Sinorhizobium saheli strain (SB2) was isolated from the root nodule of Sesbania aculeata. The Tn5 mutants (300) of SB2 were generated and studied for their nodulation efficiencies in its specific and cross-infective host plants. The mutant, SB2M3, was found to have two- and four fold higher nodulation efficiency than wild type in parent host and nonspecific host plant, respectively. SB2M3 differed from SB2 in exopolysaccharide and lipopolysaccharide content. SB2M3 was halotolerant and could grow in alkaline pH at comparatively high temperatures. Hence, it may find an application in agritechnology. [ABSTRACT FROM AUTHOR]

This is the first report on genetic studies and molecular tagging of a gene regulating flowering time in the stem nodulating legume crop Sesbania rostrata (Bremek. & Obrem.). An F2 segregating population was developed from a cross between Trombay Sesbania rostrata-1 (TSR-1, a radiation induced late flowering mutant) and S. rostrata. A phenotypic segregation ratio of 3 (normal flowering):1 (late flowering) in the F2 generation indicated that the late flowering is governed as a monogenic recessive trait. A genotypic ratio of 1:2:1 in the F2 generation, determined from phenotypic segregation patterns in 73 F3 families, confirmed the monogenic inheritance of the late flowering trait. Inter Simple Sequence Repeat (ISSR) and Amplified Fragment Length Polymorphism (AFLP) marker techniques were evaluated for their applicability as genetic marker systems in this green manure crop. Using the F2 segregating population, an ISSR marker (UBC 8811000) tightly linked to the trait was identified. Two linked AFLP markers GCTG500 and CCAT350 were also identified. They were found to be at a distance of 1.4 ± 0.034 cM and 8.0 ± 0.047 cM flanking the flowering locus respectively. The ISSR marker UBC 8811000 was converted into a Sequence Characterized Amplified Region (SCAR) marker. The single recessive mutation regulating the late flowering trait and the availability of tightly linked, flanking markers will help in identification and isolation of the gene controlling the flowering time trait. [ABSTRACT FROM AUTHOR]

The Brassicaceae species Diplotaxis tenuifolia and Brassica nigra contain high concentrations of glucosinolates, the precursors of isothiocyanates (ITCs) that can have biofumigation effects in amended soils. In a laboratory experiment, incorporation of these plants as green manures into soil was expected to suppress Rhizoctonia solani AG2-1 (ZG5), the causal agent of damping-off in canola ( Brassica napus). The manures were incorporated at 1 (1% w/w) or 5 (5% w/w) g fresh material per 100 g dry soil and incubated for 6 months at 10, 20, or 30°C and at soil water contents of 10%, 40%, or 70% of water holding capacity. R. solani survived for up to 6 months as a saprophyte in un-amended soil at all soil water contents and at 10 and 20°C. A temperature of 30°C suppressed R. solani below the level of detection in all treatments after one week. At 1% concentration, the green manures increased the colonisation of the soil by R. solani, which caused severe damping-off of canola subsequently sown in this soil treatment. Soil amendments at 1% temporarily increased soil microbial activity. The addition of B. nigra or D. tenuifolia green manure at 5% concentration suppressed the saprophytic growth of R. solani incubated at 10 or 20°C over all soil water contents and significantly increased the microbial activity at all soil temperatures and water contents. Canola sown into these pots did not succumb to damping-off. The efficiency of hydrolysis of glucosinolates in the 5% treatment in the first week of incubation ranged from 1.6% for 2-propenyl ITC, extracted from soil containing tissues of B. nigra, to 3.4% for 3-butenyl ITC extracted from soil containing tissues of D. tenuifolia. 2-propenyl ITC could not be detected after 7 d of incubation. In the longer term (weeks to months), the increase of microbial activity, caused by adding green manures at 5%, or volatiles from the green manures, most likely played a dominant role in suppressing R. solani. The impact of ITCs, if any, appears to be short-term (days). [ABSTRACT FROM AUTHOR]

Mesorhizobium huakuii is a free-living bacterium which is capable of establishing a specific symbiotic relationship with Astragalus sinicus, an important winter green manure widely used in Eastern Asia, allowing for nitrogen fixing during this process. Previous studies demonstrate that M.␣huakuii produces quorum-sensing molecules at high cell density and quorum sensing plays a role in biofilm formations. In this study, we isolated and characterized two quorum-sensing deficient mutants in M. huakuii. Analysis of the flanking region of transposon insertions indicated that autoinducer synthase related genes are not homologous to acyl homoserine lactone (AHL) synthase genes that are shared among many Gram-negative bacteria, but related to peptide synthesis, indicating that M. huakuii quorum-sensing signals are distinct from AHLs. Compared with the wild-type strains, these quorum-sensing deficient mutants promoted their growth rate and were defective in nodule formation on host plants, indicative of a critical role of quorum sensing in M.␣huakuii during the host–bacterium symbiotic interaction. [ABSTRACT FROM AUTHOR]