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Context Cropping in the Queensland Murray–Darling and Fitzroy Basins has precursors for secondary salinity – high soil salt loads and increased drainage after clearing. Aims To measure changes in deep drainage, for key tillage, traffic, and cropping systems. Methods Steady-state and transient chloride (Cl) mass-balance were applied to Cl profiles from four tillage and crop rotation trials and one controlled traffic trial in southern and central Queensland, to determine deep drainage below the root zone. Key results Large downward movement of Cl occurred after clearing. Deep drainage from transient Cl balance for cropping was a small proportion of rainfall but considerably higher than under native vegetation. Deep drainage was consistently greater under zero than conventional tillage, for both winter and summer cropping. For example, deep drainage was greatest for zero tillage (∼45 mm/year) and least for conventional, stubble mulch, and reduced tillage (2–6.3 mm/year) at the highest-rainfall site (677 mm/year). Deep drainage was 12.7 and 7.9 mm/year for zero and conventional tillage, respectively, at the lowest-rainfall site (497 mm/year). Drainage under continuous wheat conventional tillage was more than twice that where some summer crops were included. At Billa Billa, continuous wheat had greater deep drainage by three to five times than continuous sorghum for three of four tillage systems. No drainage was detected during 6 years of opportunity cropping. A pasture legume ley had only 1.7 mm/year of deep drainage. Deep drainage was less for compacted than non-compacted treatments (23.3 vs 38.2 mm/year). Conclusion and implications Increased deep drainage with zero tillage and controlled traffic can be reduced using summer crops, particularly opportunity cropping where crops are planted when soil water is sufficient, and ley pastures.

Context Tillage has temporal effects on soil organic matter and microbial attributes. Aim Three tillage systems (NT, no-tillage; MT, mulch tillage; MP, mouldboard ploughing) were used to assess the impact on soil quality indicators such as gravimetric soil water content (GSWC), soil organic carbon (SOC), total nitrogen (TN), easily extractable-glomalin (G EE), dehydrogenase (DHA), β-glucosidase (β-glu), urease (URE), acid-(AcP) and alkaline-(AlP) phosphatase over time in a sandy-loam Plinthustalf cropped annually with winter wheat and occasionally oat in eastern Free State. Methods Samples were collected during oat (October 2010, November 2010), fallow (February 2011, April 2011, May 2011) and wheat (August 2011, September 2011, October 2011) phases at 0–5 and 5–10 cm depth. Results When averaged over sampling dates, GSWC, SOC, TN and enzyme activities were 6–85% higher under NT than in MT and MP in the upper 5 cm soil. Trends changed at the 5–10 cm depth, with 20–32% higher enzyme activities recorded under MT. Soil quality indicators exhibited different trends over time, with GSWC, TN, DHA, AcP and AlP generally increasing during the fallow period and decreasing during oat and wheat phases, while β-glu was higher during both crop phases than at fallowing. URE was 33.6–174.3% higher during the oat phase than at the fallow and wheat phases. The opposite was observed with SOC, C/N ratio and G EE. Conclusions Enzyme activities were sensitive indicators, but SOC and TN can be used to assess temporal changes in soil quality in resource-limited countries. Implications However, temporal effects on SOC and TN were probably built in the long-term, hence further research focusing on multiple seasons is required.

Context Although both plant cover and mulch are considered for erosion control in arid and semi-arid regions, they have divergent impacts on soil ecology. Aim We examined the effects of orchard floor management practices on the density and diversity of soil free-living nematode communities and relevant soil abiotic properties. Methods Soils were sampled in winter in a citrus orchard in the Sharon region of Israel from plots that for 6 years had been under (1) annual native species; or (2) Avena sativa and Vicia villosa, planted between tree rows; or (3) woodchip mulching along tree rows. There were two control sites: (4) bare soil between tree rows and (5) bare soil along the tree rows (both common practice). Key results Nematode communities and their trophic diversity were significantly impacted by floor management. Significant increases in soil moisture under plant cover, and higher organic matter and water-holding capacity for all covered orchard floors could be related to nematode changes. Shifts in nematode feeding group structure suggest a shift in the type and availability of soil carbon pools. Conclusions There was a strong association between orchard floor management and soil free-living nematode communities, indicating a shift in the soil food-web structure and functionality. Bare soil harboured fewer nematodes, but more complex communities dominated by persisters, while seeded plant cover had a greater nematode abundance dominated by coloniser communities, indicating increased availability of resources. Implications Results reveal the importance of integrating biological information in performance index determinations for improving soil management decisions, suggesting these relationships as sensitive bio-indicators of soil health.

Reducing input of chemical fertiliser to cotton fields has the benefits of reduced costs, increased crop production efficiency, and positive environmental impact. We investigated the impacts of stalk management and fertiliser application on the morphology, physiological activity and nutrient use efficiency of cotton roots in arid areas when grown under drip irrigation with plastic film mulching. This 9-year field experiment involved a split-plot design with two stalk management treatments (removed or mixed with soil) as main plots and four fertiliser treatments (no fertiliser, NPK fertiliser, poultry manure, combined NPK fertiliser plus poultry manure) as subplots. Fertilisation increased root tissue mass density, specific surface area, triphenyl tetrazolium chloride reducing capacity, and glutamine synthetase, but decreased specific root length. Straw return and fertilisation increased soil available N, P and K. Nutrient use efficiencies of N, P and K in roots were sensitive to fertilisation treatment, whereas nutrient use efficiencies in total dry matter were sensitive to straw return treatment. Fertilisation increased the root:shoot ratio, root biomass, fine:coarse root mass ratio, and seed cotton yield. Combined application of NPK fertiliser and poultry manure can prompt the formation of fine roots, which maximised the contact area between poultry manure and roots, thus increasing the chance of the root acquiring mineral nutrients. Therefore, organic matter promotes the absorption of mineral nutrients by roots, thereby improving the efficiency of fertiliser utilisation.

Coastal ecosystems are under increasing pressure from land clearing along the east coast of Australia. Methods to mitigate the impacts of land clearing are needed, particularly for locally uncommon plants. In addition, there are significant knowledge gaps about cultivation methods for many wet-heath sedges. Translocation via salvage and relocation of plant populations is often the only viable ex situ, last-resort conservation option for populations threatened by clearing. We aimed to determine if translocation was an effective method for relocating a wild population of Schoenus scabripes, and how the use of organic mulch or a nitrogen-fixing companion plant affected survival, growth and nutrient concentrations of nursery-grown S. scabripes plants. Whole-plant translocation of S. scabripes plants was effective, with 62% survival at 50 months after installation. Survival of translocated nursery-grown plants was 35% at 27 months after installation. Organic mulch improved survival and health of field-established plants; however, companion plants did not improve plant health or survival. Stem and leaf winter potassium concentrations for mulched plants were significantly higher than for other treatments. Our case study demonstrated two establishment techniques for S. scabripes and suggested that whole-plant translocation of mature clumps is more effective than field establishment of nursery-grown plants.

Mechanical mastication is growing in popularity as a wildfire mitigation technique. Yet few studies quantify its effects on fire behaviour. Such information is needed by fire managers to evaluate its efficacy. Our aim was to develop an understanding of how mastication alters flaming and smouldering durations and the longevity of any effects. Flaming and smouldering duration are important determinants of soil heating and smoke emissions. We used a paired sampling design, collecting litter bed (hereafter surface fuel) samples from 15 sites with masticated and untreated vegetation in shrub-encroached Eucalyptus woodlands. We measured a range of fuel bed properties and then burnt the samples in the laboratory. Average smouldering durations increased 88% from 25 to 47 min in untreated v. masticated fuel; flaming durations increased 100% from 6 to 12 min. These changes were attributable to higher fine and coarse fuel loads in the masticated fuel bed. However, fine and coarse fuel load declined significantly over 4 years, meaning the effects of mastication on combustion duration are likely to be short-lived. Despite being a laboratory study, the results assist with evaluating mastication as a fuel treatment by demonstrating the potential magnitude of changes to flaming and smouldering duration.

Straw mulch is commonly applied to land after high-severity wildfires because of its effectiveness in reducing post-fire runoff and erosion. However, information about the effect on vegetation recovery is still scarce and usually limited to the first 2 years after wildfire. In this study, the effects of straw helimulching on vegetation recovery and species composition were assessed in 30 experimental plots established in four shrubland areas in north-west Spain 5 years after wildfire. The influence of the treatment on biomass accumulation in the medium term was also assessed. The relationships between soil burn severity, site characteristics (altitude, aspect, soil depth and percentage of stoniness) and the vegetation variables (total vegetation cover, weighted mean height of vegetation, total fuel load and litter and duff load) were also explored. Overall, the mulching treatment did not have significant effects on the variables studied. In the mulched plots, no non-native species were recorded 5 years after the wildfire. Site characteristics significantly affected the vegetation complex, but soil burn severity did not have any residual effect. The study findings indicate that straw helimulching has neutral effects on vegetation cover and composition in coastal shrublands in NW Spain in the medium term.

Our aim was to identify temperature and moisture modifications needed for improvement of seed germination, growth and establishment of the protein-rich forage legume Vicia unijuga A.Br. so that it could become large enough and store sufficient root reserves to survive in subalpine conditions. Germination tolerance of scarified V. unijuga seeds to various temperatures and water potentials was tested in the laboratory, and a 3-year field experiment was conducted in the subalpine region of China to evaluate the effects of modified soil temperature and moisture conditions generated by mulching with plastic film and barley straw on seedling emergence, growth, root nutrient reserves and subsequent overwinter performance. The highest germination percentage and rate occurred at the optimum temperature of 15–20°C, which improved these germination traits at low water potentials between –0.6 and –1.0 MPa. Higher soil temperature and water content were recorded in the plastic mulch treatment than in the control and straw mulch treatments. This enhanced establishment and accumulation of biomass and root reserve pools in the plastic mulch treatment, with nearly 100% of the plants surviving overwinter. The relative contribution of soil temperature was greater than of soil-water content to the variation in biomass and root nutrient reserves. Root starch content explained the most variation in overwinter survival. In conclusion, scarified V. unijuga seeds can germinate over a wide range of conditions, including those in the subalpine zone in spring. The plastic mulch treatment provided adequate soil temperature and water resources to improve growth and root starch reserves in first-year plants of V. unijuga, thereby improving overwinter survival in the subalpine environment.

This glasshouse pot experiment demonstrated that a new sprayable and degradable polymer reduced soil water evaporation and promoted cotton seedling emergence and establishment. The polymer was tested on two contrasting soils (sandy loam and clay), representative of those used to grow cotton in Australia. Changes in soil water content in non-treated and polymer-treated pots were monitored over 80 days, after surface or subsurface watering. Plant biomass, soil water content and soil chemical properties were determined at harvest. The polymer reduced soil water evaporation by up to 35% in sandy loam and up to 20% in clay, did not compromise seedling emergence and improved plant growth per unit water applied by up to 26.2%. The polymer underwent extensive degradation after 80 days to produce low molecular-weight polymers or oligomers and water-extractable silicon species that may have implications for plant nutrition.

The yield of direct-seeded rice has been shown to decrease after straw amendment. However, the reasons for the yield decrease, and any measures to alleviate it, are currently unknown. We hypothesised that straw return exerts negative effects on soil fertility and on root growth of direct-seeded rice, which subsequently reduces the remobilisation of reserves to grains under continuous flooding (CF); and that alternate wetting and drying (AWD) irrigation can alleviate these negative impacts. Field and greenhouse experiments were conducted to test the hypotheses, by comparing CF and AWD in combination with two wheat-straw treatments (incorporation and mulching). Under CF, wheat-straw incorporation decreased soil available phosphorus by 23–79%, root biomass by 10%, leaf biomass by 13%, and leaf area by 15% compared with the control with no straw incorporation; negative effects on these characteristics were lessened if the straw was mulched. The AWD treatment alleviated the negative effects of straw incorporation compared with CF, and straw mulching with AWD had no negative effects or resulted in positive effects. The results suggest that CF along with straw incorporation limits soil phosphorus availability, root growth and grain yield by affecting photosynthate accumulation and remobilisation. AWD irrigation mitigates these undesirable effects by decreasing soil total reductants, which subsequently increases soil pH and plant-available phosphorus. The proposed AWD treatment could be a promising strategy for the sustainable production of direct-seeded rice.

The soil degradation caused by plastic film mulching tillage in rain-fed areas of north-west China is known to affect sustainable and stable crop yields because of major losses of soil organic carbon (SOC) and nutrients. To evaluate the effects of different plastic film mulching modes on SOC and total nitrogen (STN) sequestration capacity in loessic soil, we investigated the effects of different plastic film mulching on SOC, STN, and the soil C:N ratio in semiarid areas of southern Ningxia for a 4-year period (2013–2016). Five treatments were tested: (i) the control, conventional flat planting without mulching (CK); (ii) alternating mulching and bare rows without ridges and planting in mulched rows (P); (iii) furrow planting of maize, separated by consecutive plastic film-mulched ridges (S); (iv) furrow planting of maize, separated by alternating large and small plastic film-mulched ridges (D); and (v) furrow-flat planting of maize with a large plastic film-mulched ridge alternating with a flat plastic film-mulched space (R). In the final experimental year (2016), the results showed that the mean soil bulk density at 0–60 cm depth had decreased with film mulching treatments by 2.82%, 5.90% (P < 0.05), 7.29% (P < 0.05), and 9.46% (P < 0.05) respectively, compared with CK. Film mulching increased the concentration of SOC and STN, which were ranked in order S > R/D > P > CK; however, there was no significant increase with the storage of SOC and STN. The mean soil C:N ratio was higher with mulching treatment, i.e. 2.91% (P > 0.05) higher than CK in 0–60 cm depth. Mulching treatments significantly (P < 0.05) increased the stratification ratio (SR) of SOC and soil C: N ratio from the surface (0–20 cm) to all depths compared with CK, i.e. the SR of SOC at the 0–20:20–40 cm depth significantly (P < 0.05) increased with D, R, S, and P by 14.81%, 9.47%, 14.18%, and 9.51% respectively, compared with CK.

Wild lettuce (Lactuca serriola L.) is a significant emerging agricultural and environmental weed in many countries. This invasive species is now naturalised in Australia and is claimed to cause significant losses within the agricultural industry. Sustainable management of wild lettuce has been hampered by a lack of detailed knowledge of its seed ecology. Laboratory-based studies were performed to examine the potential influence of environmental factors including temperature and light conditions, salinity, pH, moisture availability and burial depth on the germination and emergence of two spatially distant populations of wild lettuce. Results suggested that the germination of wild lettuce seeds occurred across a broad range of temperature conditions (12-h cycle: 30°C/20°C, 25°C/15°C and 17°C/7°C) for both populations. We also found that these seeds are non-photoblastic; germination was not affected by darkness, with >80% germination in darkness for both populations at all tested temperature ranges. Germination significantly declined as salinity and osmotic stress increased for both populations, with seeds from the Tempy population were more affected by NaCl >100 mM than seeds from Werribee, but in neither population was there any observed effect of pH on germination (>80% germination in both populations at all tested pH ranges). For both populations, germination significantly decreased as burial depth increased; however, the two populations differed with regard to response to burial depth treatment, whereby seeds from the Tempy population had higher emergence than those from Werribee at 0.5 cm burial depth. These results suggest that light-reducing management techniques such as mulching or use of crop residues will be unsuccessful for preventing germination of wild lettuce. By contrast, burial of seeds at a depth of at least 4 cm will significantly reduce their emergence.

During 2–5 December 2010, an area of 2500ha in the Carmel forests was consumed by a severe wildfire, causing soil erosion from the exposed slopes. Whereas most studies show that post-fire erosion rates tend to decline after the second year, in this case, we aim to address the ongoing consequences that different management practices had on soil erosion 3 and 4 years after a fire. Three management operations were applied: (a) preservation management (PM) – mulching wood chips on the burned area; (b) tree-clearing management (TCM) – burned trees were cut and removed; and (c) skid-trail formation (ST) – provisional pathways were formed while trees were dragged outside. Consequently, the objectives of the study were: (1) to monitor the effects of these post-fire practices 3 and 4 years after fire; and (2) to characterise the physical features of the eroded soil. The sediments were collected after every effective rain event over two rainy seasons (2013–14, 2014–15). TCM and ST practices resulted in significantly elevated soil-erosion yields compared to PM. The sediments following PM had a high percentage of fine material. Furthermore, PM had an evident positive effect on the soil, whereas all other practices inhibited vegetation renewal and system rehabilitation.

Decline in soil organic carbon (SOC) due to intensive tillage and removal or burning of crop residues is considered a major threat to maintaining soil quality and meeting future challenges of food production at national and global scales. Adoption of conservation-agriculture practices (no till and residue retention) is necessary to promote soil structural stability and increases in SOC content and enzyme activities. We evaluated the impact of tillage and residue-management practices on yield, soil labile-C pools, aggregate stability and soil enzyme activities after seven cycles of a rice (Oryza sativa L.)–wheat (Triticum aestivum L.) system on the Indo-Gangetic Plain of India. Treatments included four combinations of tillage and crop establishment in rice (main plots), and three combinations of tillage and residue management in wheat (subplots). Irrespective of rice-establishment method, mean grain yield of no-till wheat with rice-residue mulch (NTW+RR) was 9% and 22% higher, respectively, than of conventional-till (CTW) or no-till wheat with no rice-residue mulch. Soil C pools (very labile, labile, less-labile and non-labile) were significantly higher under a no-till dry-seeded rice (NTDSR)–NTW+RR cycle than conventional-till puddled transplanted rice–CTW. Macro-aggregates (>0.25 mm) had higher labile C pools, glomalin content and enzyme activities than micro-aggregates. NTW+RR significantly increased soil C pools within both macro- and micro-aggregates. Compared with CTW, NTW+RR increased soil dehydrogenase, cellulase and alkaline phosphatase activities by 23%, 34% and 14%, and water-soluble organic C by 31%, and increased water-stable aggregates and mean-weight-diameter. NTDSR–NTW+RR increased SOC, enzyme activity, aggregate stability and wheat grain yield. Results indicated that soil labile-C pools across aggregate fractions were the most sensitive indicators of soil quality when determining the effects of changes in management practices. Furthermore, adoption of no till and residue retention may improve sustainability in rice–wheat systems of the Indo-Gangetic Plain.

This study evaluated wheat production effects on carbon (C) fractions and soil organic C (SOC) molecular composition of a semiarid Plinthustalf in a trial established near Bethlehem. Treatments applied for 20 consecutive years included two straw management (unburned and burned), three tillage (no-tillage, ploughing and stubble mulch) and two weed control (chemical and mechanical) methods. Samples collected from 0–50 mm depth of specific treatment combinations were analyzed for SOC, soil inorganic C (SIC), permanganate oxidizable C (POXC), cold (CWEC) and hot (HWEC) water extractable C, extractable humic substances (CEX), humic acids, fulvic acids (CFA) and SOC functional groups. Humification (HI) and polymerization (PI) indices and alkyl C/O-alkyl C ratios were calculated. No-tillage combinations demonstrated potential to reverse losses of soil C fractions in the 0–50 mm layer. Increased POXC, CWEC, CEX and CFA revealed the labile nature of accumulated SOC in no-tillage, suggesting that SOC therein could be rapidly lost if no-tilled soils were again cultivated. Although the HI and PI were not always significant, their decrease in the no-tillage combinations suggest minimal decomposition, which is a benefit in Plinthustalfs with low storage capacity. Positive correlations between SIC and SOC fractions implied that an increase in SOC fractions protected SIC, resulting in its accumulation in no-tillage combinations. Functional groups seemed to mimic fractionated SOC fractions because O-alkyl C decreased with concomitant increase in alkyl, aromatic and carbonyl C. These responses highlighted that no-tillage combinations could be ideal to restore SOC quality in drought-prone agro-ecosystems dominated by sandy soils.

Water shortage is a limiting factor to crop production in North China. Mulching is a widely used approach to conserve soil water and improve crop yield. A 2-year field experiment was conducted at the Nanpi Eco-Agricultural Experimental Station of the Chinese Academy of Sciences in 2014–16, in which yields of winter wheat (Triticum aestivum L.) in a treatment with subsoil plastic film mulch were compared with non-mulch. The mulch treatment produced a 16.1% higher grain yield than the non-mulch treatment. The increase in grain yield was primarily due to a 10.1–10.9% increase in number of spikes per m2 and a 4.7–5.1% increase in number of grains per spike. Plants in the mulch treatment showed greater dry matter (DM) accumulation but similar harvest index. Yield improvement did not depend on increasing DM translocation, but was significantly related to DM accumulation at different growth stages. Increased DM accumulation before wintering, from jointing to heading and from anthesis to maturity, enhanced grain yield by promoting increased number of spikes and number of grains per spike. Soil evaporation was lower by 31.1% and transpiration increased by 28.0% in the mulch treatment, resulting in 8.9–9.4% higher water-use efficiency. Our results indicate that a subsoil plastic film mulch can effectively improve winter wheat yield and water-use efficiency under rain-fed conditions.

The present study evaluated responses of soil enzyme activity, soil micro-organisms, muskmelon root growth and muskmelon fruit yield and quality to different levels of film covering (full, half and no plastic film covering), drip pipe density (one pipe for one row (T1), three pipes for four rows (T3/4) and one pipe for two rows (T1/2)) and different lower limits of irrigation (60%, 70% and 80% of field capacity) in a greenhouse experiment using an orthogonal experimental design. Half film mulch cover resulted in higher muskmelon root activity (second only to full film covering) during the fruit swelling growth stage and promoted soil micro-organism growth. Compared with full and no film cover conditions, under half film cover mean soil urease activity was 25.16% and 1.46% higher, alkaline phosphatase (ALP) activity was 18.42% and 16.89% higher and catalase activity was 24.20% and 17.24% higher respectively. Compared with T1 and T3/4, under T1/2 mean soil ALP activity was 22.36% and 5.76% higher, catalase activity was 2.45% and 10.57% higher and muskmelon root activity during the fruit swelling period was 1.13- and 3.98-fold higher respectively. Irrigation at both 60% and 80% of field capacity improved muskmelon root length and area, soil micro-organism populations and soil urease, ALP and catalase activity. In addition, half film covering, irrigation at 80% field capacity and T1/2 improved the partial factor productivity for nitrogen, yield and fruit quality of muskmelons in the greenhouse. Therefore, these conditions appear to be the most appropriate agronomic configuration for muskmelon cultivation in greenhouses.

Intensive tillage, removal or burning of crop residues, limited organic manure use, declining irrigation water resources and scarcity of labour are the major causes of soil degradation and unsustainability of rice (Oryza sativa L.)–wheat (Triticum aestivum L.) system (RWS) in South Asia.Resource conservation technologies (RCTs) such as zero tillage (ZT), dry direct seeded rice (DSR) and crop residues retained as mulch have shown promise to increase the productivity and profitability of RWS in South Asia. Effects of RCTs on soil biological parameters are unclear and contradictory. We evaluated the effects of conservation agriculture practices on changes in soil biochemical properties at different growth stages of wheat grown as the fifth crop in RWS. Twelve treatment combinations of tillage, crop establishment and crop residue management included four main plot treatments in rice: (1) conventional tillage (CT)-DSR,(2) ZT-DSR, (3) DTR, ZT machine transplanted rice and (4) PTR, conventional puddled transplanted rice. The three subplot treatments were: (i) CTW-R, CT wheat with both rice and wheat residues removed, (ii) ZTW-R, ZT wheat with residues of both the crops removed and (iii) ZTW+R, ZT wheat with rice residue retained as surface mulch in subsequent wheat. Irrespective of rice establishment methods, mean wheat grain yield under ZTW+R was 6% and 10% greater than CTW-R and ZTW-R respectively. Soil enzyme activities increased (5–18%) under ZTW+R compared with ZTW-R and CTW-R at different growth stages of wheat. The residual effect of rice establishment methods was significant on soil enzyme activities during wheat cropping, which were highest under ZT-DSR followed by CT-DSR, DTR and PTR. Soil organic carbon content in the 0–7.5 cm layer was significantly higher (7–9%) under the ZTW+R treatment compared with all the other treatments. Principal component analysis (PCA) identified three enzyme activities (dehydrogenase, fluorescein diacetate and phosphatase), and soil organic carbon content as the most sensitive indicators for assessing soil quality for RWS based on conservation agriculture. The PCA discriminated rice establishment systems with rice residue as surface mulch from rice establishment systems without rice residue and the maximum tillering stage from the other stages of wheat. The present study provided reliable biochemical indicators to monitor soil biological quality changes in response to conservation agriculture practices in RWS.

Rain-harvesting planting can improve crop biomass and enhance precipitation use efficiency in rainfed semiarid areas. In this study, field trials were conducted during summer 2007–2010 to determine the impacts of different mulching patterns in rainfall harvesting planting on spring corn growth and development in a typical semihumid dryland farming area of the Loess Plateau in China, which is characterised by spring droughts. Rain-harvesting ridges and planting furrows were mulched with 8% biodegradable film (RCSB), liquid film (RCSL), or not mulched (RCSN), and bare land drilling without mulching served as the control (CF). We found that the rain-harvesting effects of ridges and the evaporation-inhibiting and moisture-conserving effects of mulching materials during the spring corn growing season significantly increased water storage in the 0–100cm soil layer (P0.05) of the treatments on water storage. During 2007–2010, the average plant height increased by 26.6%, 15.4%, and 11.1% under RCSB, RCSL, and RCSN relative to CF respectively, whereas the per plant biomass increased by 26.6%, 15.4%, and 11.1% under these treatments, and the grain yield increased by 32.3%, 17.5%, and 15.0%. Therefore, in the semihumid dryland farming areas of the Loess Plateau, rain-harvesting planting greatly increased the growth, development, and dry matter accumulation by spring corn, thereby enhancing its biomass yield, whereas the plastic-covered ridges and furrows mulched with biodegradable films substantially increased the yield-enhancing effects.

Straw mulch is commonly used for post-fire erosion control in severely burned areas but this practice can introduce non-native species, even when certified weed-free straw is used. Rice straw has recently been promoted as an alternative to wheat under the hypothesis that non-native species that are able to grow in a rice field are unlikely to establish in dry forested habitats. We investigated this hypothesis in the severely burned areas of the 2013 Rim Fire in the Sierra Nevada that were treated with rice straw post-fire. In 2014, we installed 134 plots in mulched and control areas with >95% tree mortality and re-measured a subsample in 2015. Mulched areas had significantly higher non-native forb cover, non-native graminoid cover and non-native species richness. In addition, 25 non-native species occurred exclusively in mulched areas; collectively, these responses contributed to more homogenous plant communities in mulched areas than in unmulched areas in 2015. In contrast, mulch had no effect on total plant cover, and conifer regeneration densities were generally unaffected with the exception of a slight positive effect on Douglas-fir. We recommend more stringent testing for weed-free certification and that funding for non-native species eradication be included with post-fire rehabilitation plans.

Biochar has been widely proposed as a relatively novel approach to improve soil quality and increase crop productivity, but its underlying mechanisms are not well understood. A large root system in plants is either a constitutive or an inducible trait dependent on the uptake of resources and the production of shoot dry matter. Here a field experiment was conducted to investigate the effects of biochar amendment on the dynamic growth and development of maize (Zea mays L.), both above- and belowground, and to explore the relationship between soil condition, root traits and shoot biomass over two growing seasons on the Loess Plateau in northern China. Biochar was added to a maize field at rates of 0, 10, 20 and 30 t ha–1 without mulching and at rates of 0 and 20 t ha–1 with film mulching before sowing the first crop. The application of straw biochar with 30 t ha–1 decreased soil bulk density by 12% and increased soil total porosity by 13% in the 0–10-cm soil layer 6 months after biochar addition. Biochar amendment increased soil organic carbon, total soil nitrogen, carbon : nitrogen ratio, and available phosphorus and potassium at the end of each growing season. Although, root growth was inhibited at a rate of 30 t ha–1 in the early stage of the first year, biochar amendment exhibited a positive effect in other stages, resulting in higher root weight density, root length density and root surface-area density. These responses led to higher growth rates, maize biomass, grain yields and uptake of nitrogen, phosphorus and potassium as the rate of biochar addition increased. Film mulching with biochar amendment achieved the greatest root and shoot biomass and grain yield in both crops, despite differences in climate conditions. Biochar aged in the field for 2 years had the same effect on soil properties and crop production, suggesting that the application of straw biochar may be a promising option for increasing productivity in semi-arid farmland.

Mulch materials of different origin and colour are available in the agricultural sector as sustainable alternatives to the use of polyethylene (PE). Mulching modifies soil temperature and consequently affects crop yields. This work assessed the thermal and productive responses of different mulch materials in two different geo-climatic conditions during a 3-year integrated field study on processing tomato (Lycopersicon esculentum Mill.). Two biodegradable plastic mulches (BD1, BD2), one oxo-degradable material (OB), two types of paper (PP1, PP2) and one barley-straw cover (BS) were compared with two control treatments: black PE and manual weeding (MW). Soil temperature variables (maximum, minimum and mean temperature, soil growing degree-days and soil temperature amplitude) and production variables (marketable and total yield, mean fruit weight) were considered. Thermally, PE could be considered an atypical mulch causing higher temperatures in the soil, but it is not associated with a higher yield. Responses of PE, PP2 and MW were independent of the geo-environmental conditions, whereas OB, BD1 and BD2 had similar thermal and productive responses to each other in different environments. Tomato yield was correlated positively only with the minimum soil temperature, especially when excluding PE.

Water deficiency is the main limiting factor for crop growth in rain-fed areas. Mulching can affect the soil microclimate (soil water and temperature) and influence the grain yield of crops. A field experiment was conducted to determine the effect of different mulching materials on soil temperature, soil water, crop growth and yield, and water use efficiency (WUE) in spring maize (Zea mays L.) between 2009 and 2011 in Heyang County, Shaanxi, China. The field experiment used five mulch treatments: polyethylene film (PM), biodegradable polymer film (BM), maize straw (MM), liquid membrane (LM), and an uncovered control (CK). In the early stage of maize growth, the topsoil temperatures (0–10cm) in the PM and BM treatments were significantly (P0.05) in soil temperature or soil water in the LM treatment during the entire growing season. Maize yield increased significantly (P0.05) differences were observed between these two treatments. Biodegradable polymer film is useful in reducing environmental pollution caused by polyethylene film and could potentially replace polyethylene film during agricultural production in the Northwestern Loess Plateau, China.

Applying a mulch of oil palm empty fruit bunches (EFBs) from processing mills to newly transplanted oil palm is widely practiced for sustainable management and recycling of solid waste from the oil palm industry. Thus, it is important to understand the decomposition and mass loss of EFBs and its nutrient release pattern for better fertility management. The present study was conducted in a newly transplanted oil palm field to investigate the mass loss of applied EFBs and nutrient release pattern over a 12-month period. The treatments evaluated in the present study were: (1) chemical fertiliser (CF) application only; (2) EFB application only; and (3) EFB and CF application (EFB+CF). The treatments were applied immediately after transplanting 13-month-old palms. EFBs were applied around the base of the oil palm at a rate of 170 kg palm–1. Results showed that 50% dry weight of EFB and EFB+CF was lost within 90 days of application. The C : N ratio decreased from 82 to 20 after 180 and 172 days in EFB and EFB+CF respectively. The breakdown of lignin in EFBs was found to be significantly accelerated by the introduction of CF. Soil properties were improved by EFB application with an increase in pH, total mineral N and exchangeable K of the top soil. After 317 DAP, the soil organic C content subjected to treatment with EFB only and EFB+CF was significantly higher (i.e. 1.7%) when compared with that subjected to the control treatment (i.e., 1.3%). Total N increased significantly from 0.06% to 0.12% for both EFB treatments.

Juniper (Juniperus spp.) and piñon (Pinus spp.) trees have encroached millions of hectares of sagebrush (Artemisia spp.)–bunchgrass communities. Juniper–piñon trees are treated to reduce canopy fuel loads and crown fire potential. We measured the effects of juniper–piñon infilling and fuel-reduction treatments on fuel load characteristics at four locations in Utah. At each location, treatment areas were burned, left untreated, or trees were cut or masticated in a randomised complete-block design. We measured standing and downed fuels by size and type along 30-m transects on 15 subplots (30 × 33 m) per location before and 1–3 years after treatment. Increased tree cover was associated with decreased shrub and herbaceous fuel loads (P

There is evidence that the soil health in Taveuni, Fiji is deteriorating over time threatening livelihoods of taro producers. The present study was conducted to understand the soil nutrient management practices followed by taro farmers in Taveuni. The study revealed that the farmers in Taveuni use various organic and chemical fertilizers and various other soil fertility management practices such as mulching, crop rotation with legumes, yagona and agroforestry. The quantity of nitrogen, phosphorous and potash (NPK) applied to taro crop on different types of soils was meager. The study further revealed that there was imbalanced and insufficient use of chemical fertilizers and organic sources of soil nutrients. The main cause of low use of fertilizers was that the farmers in Taveuni do not know the fertility status of their farms as no soil testing was ever done and majority of them are also not fully aware of various low-cost organic methods of maintaining soil fertility of farms.

Over 1200 post-fire assessment and treatment implementation reports from four decades (1970s–2000s) of western US forest fires have been examined to identify decadal patterns in fire characteristics and the justifications and expenditures for the post-fire treatments. The main trends found were: (1) the area burned by wildfire increased over time and the rate of increase accelerated after 1990; (2) the proportions of burned area assessed as low, moderate and high burn severity likely have remained fairly constant over time, but the use of satellite imagery that began c. 2000 increased the resolution of burn severity assessments leading to an apparent decreased proportion of high burn severity during the 2000s; (3) treatment justifications reflected regional concerns (e.g. soil productivity in areas of timber harvest) and generally reflected increased human encroachment in the wildland–urban interface; (4) modifications to roads were the most frequently recommended post-fire treatment type; (5) seeding was the most frequently used land treatment, but declined in use over time; (6) use of post-fire agricultural straw mulch has steadily increased because of proven success; and (7) the greatest post-fire expenditures have been for land treatments applied over large areas to protect important resources (e.g. municipal water sources).

Farmers continuously remove crop residues for use as building materials, fuel and animal feed or bedding as well as to avoid difficulties during tillage operations. Therefore, demonstrations of the benefits of recycling crop residues are necessary. The aim with this study was to evaluate the influence of different wheat production management practices on acidity and some essential nutrients from a long-term trial on a Plinthosol in semi-arid South Africa. The trial was set up in 1979, and since then two methods of straw management (unburned and burned), three methods of tillage (no-tillage, stubble mulch, and plough), two methods of weed control (chemical and mechanical), and three levels of nitrogen (N) fertiliser (20, 40 and 60 kg ha–1) have been applied. Soil samples were collected in June 2010 at depths of 0–50, 50–100, 100–150, 150–250, 250–350 and 350–450 mm from plots that received 40 kg N ha–1 and were analysed for pH, phosphorus (P), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn). Results obtained showed that straw burning resulted in higher P and Mn but lower Cu than no-burning. No-tillage, and to some extent stubble mulch, suppressed soil acidification and increased P and Zn compared with ploughing, especially in the surface layers where crop residues accumulate. In contrast, mouldboard ploughing and stubble mulch increased Cu more than no-tillage, possibly due to the strong affinity of organic matter for Cu. Tillage effects on Mn were inconsistent and difficult to explain. Chemical weeding also improved P, probably because of the pesticide application, but resulted in lower pH and Cu values compared with mechanical weeding. Treatment combinations also had an influence on P and, to a lesser extent, on soil pH and Cu, which might be due to the higher organic matter present in no-tilled soils. Irrespective of straw management or weed-control methods, no-tillage resulted in higher P than did ploughing and stubble mulch. Nutrient concentrations and pH values were sufficient for wheat growth under all treatments. However, although the nutrients were highest under straw burning, no-tillage and, to some extent, stubble mulch, wheat yield was higher with unburned straw and mouldboard ploughing. Therefore, an integrated approach from various disciplines is recommended to identify and rectify yield-limiting factors under conservation tillage systems.

Long-term studies of soil organic carbon dynamics in two- and three-crop rotations in irrigated cotton (Gossypium hirsutum L.) based cropping systems under varying stubble management practices in Australian Vertosols are relatively few. Our objective was to quantify soil organic carbon dynamics during a 9-year period in four irrigated, cotton-based cropping systems sown on permanent beds in a Vertosol with restricted subsoil drainage near Narrabri in north-western New South Wales, Australia. The experimental treatments were: cotton–cotton (CC); cotton–vetch (Vicia villosa Roth. in 2002–06, Vicia benghalensis L. in 2007–11) (CV); cotton–wheat (Triticum aestivum L.), where wheat stubble was incorporated (CW); and cotton–wheat–vetch, where wheat stubble was retained as in-situ mulch (CWV). Vetch was terminated during or just before flowering by a combination of mowing and contact herbicides, and the residues were retained as in situ mulch. Estimates of carbon sequestered by above- and below-ground biomass inputs were in the order CWV >> CW = CV > CC. Carbon concentrations in the 0–1.2 m depth and carbon storage in the 0–0.3 and 0–1.2 m depths were similar among all cropping systems. Net carbon sequestration rates did not differ among cropping systems and did not change significantly with time in the 0–0.3 m depth, but net losses occurred in the 0–1.2 m depth. The discrepancy between measured and estimated values of sequestered carbon suggests that either the value of 5% used to estimate carbon sequestration from biomass inputs was an overestimate for this site, or post-sequestration losses may have been high. The latter has not been investigated in Australian Vertosols. Future research efforts should identify the cause and quantify the magnitude of these losses of organic carbon from soil.

Research on the amounts of carbon that can be added to Vertosols of New South Wales and Queensland by crop roots in irrigated cotton farming systems is sparse. The objective of this study was to determine the amounts of carbon added to soil by roots of wheat (Triticum aestivum L.) and purple vetch (Vicia benghalensis L.) sown in rotation with irrigated cotton (Gossypium hirsutum L.). Measurements were made from 2008 to 2010 in an ongoing experiment near Narrabri, northern NSW, using a combination of soil cores and minirhizotron observations. The experimental treatments were: cotton monoculture; cotton–vetch (CV); cotton–wheat, in which wheat stubble was incorporated into the beds with a disc-hiller (CW); and cotton–wheat–vetch, in which wheat stubble was retained as in-situ mulch (CWV). Vetch was killed by a combination of mowing and contact herbicides, and the residues were retained as in situ mulch. Root length per unit area of vetch in CWV and wheat in both CW and CWV was comparable, although wheat had a higher concentration of roots in surface 0.10 m. Root growth of the CV treatment was sparse. Root carbon available for addition to soil was greater with vetch than with wheat and was in the order: vetch in CWV (5.1 t C/ha.year) > vetch in CV (1.9 t C/ha.year) > wheat in CW (1.6 t C/ha.year) = wheat in CWV (1.7 t C/ha.year). Intra-seasonal root mortality accounted for 12% of total root carbon in vetch and 36% in wheat. The remaining fraction consisted of carbon in the root mass at the end of the growing season. Carbon sequestered by root inputs of the rotation crops was estimated to be ~0.34 t C/ha.year for the vetch and wheat crops in the CWV rotation, 0.10 t C/ha.year for vetch in CV, and 0.08 t C/ha.year for wheat in CW. Rotation CWV was, therefore, the most effective in sequestering carbon from roots.

Comparative studies of soil quality and energy use in two- and three-crop rotations in irrigated cotton (Gossypium hirsutum L.) based cropping systems under varying stubble management practices in Australian Vertosols are sparse. Our primary objective was to quantify selected soil quality indices (salinity, sodicity, exchangeable cations, nitrate-N, pH), crop yields, and greenhouse gas emissions in four irrigated cotton-based cropping systems sown on permanent beds in a Vertosol with subsoil sodicity near Narrabri in north-western New South Wales. A secondary objective was to evaluate the efficacy of sowing vetch in rotation with cotton over a long period on the incidence of black root-rot in cotton seedlings. Results presented in this report pertain to the period June 2005–May 2011. The experimental treatments were: cotton–cotton; cotton–vetch (Vicia benghalensis L.); cotton–wheat (Triticum aestivum L.), where wheat stubble was incorporated; and cotton–wheat–vetch, where wheat stubble was retained as in-situ mulch. Vetch was terminated during or just before flowering by a combination of mowing and contact herbicides, and the residues were retained as in-situ mulch. Soil pH, electrical conductivity (EC1 : 5), Cl–, NO3–-N, exchangeable cations, exchangeable sodium percentage (ESP), electrochemical stability index (= EC1 : 5/ESP), and EC1 : 5/ESC (exchangeable sodium concentration) were evaluated in samples taken from the 0–1.2 m depth before sowing cotton during late September or early October of each year. Incidence of black root-rot was assessed 6 weeks after sowing cotton. Compared with sowing cotton every year, including wheat in cotton-based cropping systems improved cotton yield and reduced soil quality decline, emissions of carbon dioxide equivalents (CO2-e) per unit area, and CO2-e emissions per unit of cotton yield. Including vetch in the rotation was of negligible benefit in terms of yield and CO2-e emissions per unit of yield. The rate of soil quality decline was unaffected by including vetch in a cotton–wheat rotation but was accelerated when included in a cotton–cotton sequence. Among all cropping systems, soil quality was best with cotton–wheat and cotton–wheat–vetch but poorest with cotton–vetch. Although CO2-e emissions associated with growing 1 ha of cotton could be reduced by 9% by growing vetch because of substituting fixed atmospheric N for N fertiliser derived from fossil fuels, this advantage was partly negated by the emissions from farming operations associated with growing a vetch crop. Relative to a two-crop rotation (one cotton–one rotation crop), negligible benefits in terms of yield, soil quality, greenhouse gas emissions, and black root-rot control accrued from a three-crop rotation (one cotton–two rotation crops). Incidence of black root-rot increased as the number of cotton crops sown increased. In addition to the cropping systems, soil quality indices and yield were significantly influenced by irrigation water quality and climate.

Comparative studies of drainage and leaching in irrigated cotton (Gossypium hirsutum L.) based cropping systems in Australian Vertosols are sparse. Our objective was to quantify soil water storage, drainage, and leaching in four cotton-based cropping systems sown on permanent beds in an irrigated Vertosol with subsoil sodicity. Drainage was inferred using the chloride mass-balance method, and soil water storage and leaching were measured with a neutron moisture meter and ceramic-cup water samplers, respectively, from September 2005 to May 2011 in an ongoing experiment. The experimental treatments were: CC, cotton monoculture, summer cotton with winter fallow; CV, cotton–vetch (Vicia benghalensis L.) rotation with vetch stubble retained as in-situ mulch; CW, cotton–wheat (Triticum aestivum L.), with wheat stubble incorporated and a summer–winter fallow; and CWV, cotton–wheat–vetch, with wheat and vetch stubbles retained as in-situ mulch and summer and spring fallows. Soil water storage was generally highest under CW and CWV and least under CV. An untilled short fallow (~3 months) when combined with retention of crop residues as surface mulch, as in CWV, was as effective in harvesting rainfall as a tilled long fallow (~11 months) with stubble incorporation, as in CW. Drainage under cotton was generally in the order CW ≥ CWV > CC = CV, all of which were considerably greater than drainage during fallows. Except for very wet and dry winters, drainage under wheat rotation crops was greater than that under vetch. During wet winters, saturated soil in the 0–0.6 m depth of treatments under fallow resulted in more drainage than in the drier, cropped plots. No definitive conclusions could be made with respect to the effects of cropping systems on salt and nutrient leaching. Leachate contained less nitrate-nitrogen, magnesium, and potassium, but leachate electrical conductivity was ~6 times higher than infiltrated water. The greater salinity of the leachate may pose a risk to groundwater resources.

Precipitation is the major factor limiting crop growth in the semi-arid Loess Plateau region of China. Ridge-and-furrow rainfall harvesting systems (RFRHS) with mulches are used to increase water availability to crops, thereby improving and stabilising agricultural production in the semi-arid region of China. We conducted a field experiment from 2007 to 2010 in the Weibei Highlands of China, to determine the influence of RFRHS with different mulching patterns on soil water content, temperature, water-use efficiency, and maize yield (Zea mays L.). Ridges were covered with standard plastic film in all RFRHS treatments, while different furrow treatments were mulched with standard plastic film (PP), biodegradable film (PB), maize straw (PS), or liquid film (PL), or left uncovered (P). A conventional flat treatment without mulching was used as the control. In the early stage of maize growth, the topsoil temperature (5–20 cm) under PP and PB was significantly (P

Biosolids, poppy mulch (PM), and poppy seed waste (PSW) were applied to soils in barley and wheat field trials in two areas of Tasmania to determine crop and soil responses and the potential for these materials to substitute for inorganic fertiliser. Lime-amended biosolids (LAB) was applied at one, two, and five times the nitrogen-limiting biosolids application rate (NLBAR). Anaerobically digested biosolids (ADB) was applied at the NLBAR, and PM and PSW were applied at industry-recommended rates. The results indicated that ADB, LAB, PM, and PSW can substitute for inorganic fertiliser in meeting plant nutrient requirements but may be releasing more plant-available N than guideline assumptions. However, organic amendments are less easily managed and applied than inorganic fertiliser, and release of plant-available N from organic amendments may be too rapid for plant uptake to prevent leaching losses. LAB can also leave elevated residual extractable phosphorus in soil after two cereal crops, and PM and LAB can increase soil pH. Microbial biomass showed an inconsistent, and in some cases unexpected, response to organic amendments after 1 year and no significant relationship to changes in soil carbon.

This study assessed the effectiveness of different methods of reducing soil erosion after a severe wildfire in Galicia (NW Spain). The treatments compared were: straw mulch (2.5 Mg ha–1), wood-chip mulch (4 Mg ha–1), cut-shrub barriers and control. Straw mulch provided an initial ground cover of 80% and the wood chips only 45%. Sediment yields were measured by means of sediment fences in 500-m2 bordered plots. During the first year after wildfire, mean precipitation was 1520 mm. The mean sediment yield in the control plots was 35 Mg ha–1. During this period, only straw mulch application significantly reduced soil erosion relative to controls (66%). The mean sediment yields in the wood-chip mulch and erosion barrier treatments, 33 and 30 Mg ha–1 respectively, were similar to rates in the untreated plots (35 Mg ha–1). Soil erosion decreased sharply during the second year after wildfire when mean precipitation was 1194 mm. Vegetation regrowth was very fast and treatments had no significant effect on the rate of recovery of vegetation cover, which was ~80% at the end of the study. The results obtained showed that ground cover was a key factor in determining post-fire soil loss. Stabilisation treatments such as wood-chip mulch and erosion barriers were not effective in reducing soil loss relative to the untreated control.

Oversupply of potassium (K) to grape vines can result in high grape berry K and pH, leading to difficulty in wine making and low wine quality. There is concern that application of mulch to grape vines may increase K supply and the associated risks. The effect of composted mulch from green wastes was investigated in a field trial involving six vineyards in New South Wales on soils commonly used for viticulture production in Australia, over three seasons (2006–08). Significant increases in extractable soil K were detected as a result of mulch application. Higher berry K and pH were also observed due to the mulch treatments, with the changes dependent on season and mulch rate. Increases in berry K were significantly related to the higher soil exchangeable K. The mean increase in berry K due to a mulch rate of 153 m3/ha was 123 mg/kg. The mean increase in berry pH was 0.02 units observed in two seasons. Application of mulch can increase berry K and pH, but the changes are small compared with variations observed among vineyard sites and between seasons.

In the subtropical dairy region of Australia, poor establishment of short-term ryegrass (Lolium multiflorum) oversown into tropical grass pastures is a common occurrence requiring re-sowing. A survey of subtropical dairy farmers was undertaken to relate management practices used in oversowing ryegrass to sward establishment and subsequent growth. Two glasshouse studies were also conducted to examine (1) the effect of temperature, ploidy, seeding depth, and mulch cover on ryegrass emergence and (2) the effect of temperature and ploidy on growth and development of ryegrass seedlings. Subtropical dairy farmers only used grazing management to control the growth and residue levels of the tropical grass pasture before oversowing. The average residue was 1200 kg DM/ha to a 5 cm height, and where the residue amount and height were higher, the ryegrass failed to establish. Tetraploid cultivars were preferred in early sowings and diploid cultivars were favoured in later sowings. When direct-drilled, either seed type was sown to a depth of 1–3 cm. A 20–30 kg/ha sowing rate was common for diploids and was at least 2× that for tetraploids. A seedling count 600 plants/m2. The ryegrass seedling emergence study was conducted at 25/15°C (day 0600–1800 hours)/(night 1800–0600 hours) for 14 days after sowing and then repeated at 20/10°C. The treatment combinations were 2 seed types (tetraploid or diploid) × 4 sowing depths (0, 1, 3, or 6 cm) × 3 mulch heights (1, 5, or 10 cm above surface). The main effects, seed type, sowing depth, and mulch height had significant (P

Mulch is widely used to encourage establishment and growth of replanted vegetation in forest restoration. The presence of mulch may also benefit soil and litter dwelling arthropods, but little is known about how recolonizing arthropods respond to different types and quantities of mulch used in forest restoration. We employed a manipulative field experiment to assess the effects of mulch type and depth on the colonization patterns of ants and other soil and litter arthropods in created habitat patches. Experimental habitat patches of 2.5 m x 2.5 m were established by adding sterilized hay (a conventionally used mulching material) or forest woodchip (a structurally more complex alternative) at two depths (shallow 3?5 cm, deep 10?15 cm) to create conditions similar to those during the initial stages of rainforest restoration. These were deployed at five sites adjacent to rainforest remnants on the Maleny plateau of subtropical eastern Australia. Despite its simple composition, hay performed better than woodchip in facilitating colonization by arthropods characteristic of rainforest. Shallow hay was favored by rainforest-dependent ant species. Although the results supported the use of hay over woodchip as habitat for rainforest arthropods, neither hay nor woodchip excluded arthropods characteristic of pasture.

One of the most important problems in the Loess Plateau of China affecting sustainable agriculture is inefficient nutrient use. Field experiments were conducted to study the effects of different soil management practices on the nitrogen (N) dynamics and winter wheat yield on a loess soil in Luoyang, Henan province, China. The results showed that subsoiling with mulch (SS) consistently increased the yield of winter wheat primarily by better water harvest compared with conventional tillage (CT). The influence on yield of no till with mulch (NT) depended on the amount of precipitation. TC (2 crops per year) lowered the winter wheat yield mainly due to the unfavourable soil moisture conditions after growing peanut in summer; however, the harvested peanut gained an extra profit for the local farmer. N uptake by grain and straw and N export was highest for SS. Changes in frequency and intensity of tillage practice altered soil total N content and its distribution along the slope. SS and NT increased the N content of the surface layer (0–0.20 m) compared with CT, but there was no significant effect in deeper soil layers. Considerable amounts of nitrate-N were left in the profile 0–1.60 cm just after harvest under all treatments. The cumulative nitrate-N content to a depth of 1.60 m on average was 282 kg/ha, of which 56 kg/ha was in the layer 1.20–1.60 m, which is an indication of considerable nitrate leaching. From data of 7 consecutive years between 1999 and 2006, it could be concluded that SS resulted in the highest yield and total N content in the surface layer, and is the most sustainable tillage option for the circumstances of the study area.

The use of straw mulching has been demonstrated to decrease soil loss and to improve soil moisture and soil organic matter content in conjunction with papaya (Carica papaya) cultivation. Mulching may also benefit soil biota. In this study, mulching was demonstrated to significantly (P < 0.05) improve arbuscular mycorrhizal fungal colonisation of papaya roots (by a factor of 2.4), but decreased spore density and species diversity (by a factor of 1.5), compared with cultivation in bare ground. The genera Glomus, Acaulospora, Gigaspora and Sclerocystis dominated in both mulched and bare ground systems. The increased mycorrhizal activity in the mulched treatments was matched by an increase in leaf phosphorus in 1995 but not in 1997.

About 0.3 million t/year of composted garden organics (CGO) including mulches and soil conditioners are produced annually in New South Wales, Australia, although only a small proportion of this material (

Lack of suitable machinery is a major constraint to direct drilling into combine-harvested rice residues due to the heavy straw load, and the presence of loose tough straw deposited by the harvester. Therefore, most rice stubbles are burnt in the mechanised rice–wheat systems of south Asia and Australia, as this is a rapid and cheap option, and allows for quick turn around between crops. As well as loss of organic matter and nutrients, rice stubble burning causes very serious and widespread air pollution in the north-west Indo-Gangetic Plains, where rice–wheat systems predominate. A novel approach with much promise is the Happy Seeder, which combines the stubble mulching and seed drilling functions in the one machine. The stubble is cut and picked up in front of the sowing tynes, which engage bare soil, and deposited behind the seed drill as mulch. Evaluation of the technology over 3 years in replicated experiments and farmers’ fields in Punjab, India, showed that establishment of wheat sown into rice residues with the Happy Seeder was comparable with establishment using conventional methods (straw burnt followed by direct drilling or cultivation before sowing) for sowings around the optimum time into stubbles up to 7.5 t/ha. For late sowings, plant density declined significantly at straw loads above 5 t/ha. The mulch also reduced weed biomass by ~60%, and reduced soil evaporation. Yield of wheat sown around the optimum time into rice residues, using the Happy Seeder, was comparable with or higher than yield after straw removal or burning, in replicated experiments and farmers’ fields, for straw loads up to 9 t/ha. In farmers’ fields there was an average yield increase of 9 and 11% in 2004–05 and 2005–06, respectively, compared with farmer practice. For sowings after the optimum time, yield declined significantly at straw loads greater than 7.5 t/ha. The Happy Seeder offers the means of drilling wheat into rice stubble without burning, eliminating air pollution and loss of nutrients and organic carbon due to burning, at the same time as maintaining or increasing yield.

Two revegetation field trials were undertaken on chronically bare acid sulfate soil scalds on grazing properties in the Hawkesbury and Macleay catchments of New South Wales, Australia. The aim was to test the effectiveness of various low cost and readily accessible techniques to encourage revegetation (via existing seedbank or surrounding vegetation) of the scalded sites. The trial at the more efficiently drained Hawkesbury site used a combined treatment of ridging (R), mulching (M) and liming (L) (i.e. R–M–L) compared with a control, within a fenced area. At the more waterlogged Macleay site, various elements of the combined treatment (i.e. R, M, R–M, R–L, R–M–L) were compared with a control, within a fenced area. Vegetation occurrence, biomass and species were tested, along with pertinent soil parameters (pH, salinity, soil moisture, soluble metals). Soil testing was undertaken at 2 depth levels to represent the seed germination zone (0–1 cm), and the potential root zone (1–10 cm). At the Hawkesbury site, the combined treatment (R–M–L) caused significantly greater vegetation occurrence and biomass, lower salinity, higher pH and increased soil moisture. At the Macleay site, results were more variable, but similar to the Hawkesbury trial as the site dried out. Mulching was the single most important treatment. All mulched sites had significantly more vegetation than the control, reaching 100% coverage in the R–M–L plots. Stock exclusion alone produced minimal results. Ridging alone was counterproductive. Liming without mulching caused proliferation of an insubstantial and transient vegetation species (Isolepis inundata). Most interesting was the different vegetation species encouraged by the different mulch treatments: treatment M was dominated by the sedge, Eleocharis acuta; treatment R–M was an even mix of Eleocharis acuta and native water-tolerant grasses (Paspalum distichum and Pseudoraphis paradoxa); treatment R–M–L was dominated by the aforementioned native grasses. These grasses are highly favoured for both economic (highly palatable to stock) and environmental (thick mulch cover, self seeding) objectives. The results demonstrate that revegetation of acid sulfate soil scalds is possible, and different treatments can influence vegetation species composition.

Firebrands or embers are produced as trees and structures burn in wildland–urban interface (WUI) fires. It is believed that firebrand showers created in WUI fires may ignite vegetation and mulch located near homes and structures. This, in turn, may lead to ignition of homes and structures due to burning vegetation and mulch. Understanding the ignition events that are due to firebrands is important to mitigate fire spread in communities. To assess the ignition propensity of such materials, simulated firebrands of uniform geometry, but in two different sizes, were allowed to impinge on fuel beds of shredded hardwood mulch, pine straw mulch, and cut grass. The moisture content of these materials was varied. Firebrands were suspended and ignited within the test cell of the Fire Emulator/Detector Evaluator (FE/DE) apparatus. The FE/DE was used to investigate the influence of an air flow on the ignition propensity of a fuel bed. Ignition regime maps were generated for each material tested as a function of impacting firebrand size, number of deposited firebrands, air flow, and material moisture content.

Saline-sodic clay minespoil materials excavated during open-cut coal mining in central Queensland, Australia, pose significant challenges for revegetation, particularly where suitable topsoil capping is not available. We examined the ability of sawdust or straw mulch amendments to ameliorate the adverse properties of these minespoils and improve the success of revegetation efforts. In laboratory studies, mulch application improved infiltration, increased soil moisture retention and reduced surface crust strength. In the field, mulches incorporated to a depth of 0.15 m at application rates of at least 20 t/ha straw or 80 t/ha sawdust were needed to mitigate against capillary rise of salts during drying cycles and support satisfactory vegetation cover. Further research is needed to determine whether improvements are maintained beyond the 4-year trial period reported here.

Field experiments were conducted to evaluate the effects of 4 rice farming systems (fallow, white clover (WC), rye and rye + WC) at 3 straw mulching levels (0, 500, 1000 g/m2) under no-till, direct-sown and unfertilised rice-based cropping systems in a temperate climate in Japan. From 1999 to 2001, white clover and rye were grown during winter (November–May) in Ehime Prefecture (33°57′N, 132°47′E, 15 m a.s.l.) to evaluate the effects on rice growth and yield-related characteristics. Seed germination was greatest in clover–rice cropping systems (60, 68%) followed by rye + WC–rice (56, 57%) for the 0 and 500 g/m2 mulching treatment, respectively. Rice yielded 1.26–4.12 t/ha in 2000 and 0.54–3.80 t/ha in 2001. Panicle number ranged from 84 to 248 and 47 to 323/m2 in 2000 and 2001, respectively. WC with light rice straw mulching in rotation with rice produced moderate rice yield in no-till, unfertilised, direct-sown rice-based cropping systems. Heavy mulching of rice straw in the WC and WC + rye is not recommended because it leads to a decrease in white clover biomass production. However, straw mulching in fallow–rice and rye–rice cropping systems is essential for improving seed germination and seedling establishment while providing nutrients to rice at later growth stages.

Mastication of woody shrubs is used increasingly as a management option to reduce fire risk at the wildland–urban interface. Whether the resulting mulch layer leads to extreme soil heating, if burned, is unknown. We measured temperature profiles in a clay loam soil during burning of Arctostaphylos residues. Four mulch depths were burned (0, 2.5, 7.5 and 12.5 cm), spanning typical conditions at forested sites in northern California with dense pre-mastication shrub cover. Two soil moisture contents were compared at each fuel depth to simulate spring prescribed burning (moist soil) and late-season wildfire (dry soil). Maximum temperatures reached 600°C on the surface of dry soils and were 100–200°C lower for moist soil. Heating was extensive in dry soil for the two deepest mulch depths, exceeding the lethal threshold for plants (60°C) for a minimum of 7 h throughout the 10-cm soil profile. Minimal heat pulse was found with less mulch. Moist soil also dampened heat penetration; peak temperatures exceeded 60°C only to 2.5 cm in the soil profile for all but the deepest mulch layer. No adverse effects of burning on water repellency were found in dry or moist soil. The potential for biological damage from soil heating during fire exists following mastication, particularly in dry soil with a mulch depth of 7.5 cm or greater. Field projections indicate that up to one-fourth of treated areas with dense pre-mastication vegetation would surpass lethal soil temperatures during a surface wildfire.

To determine the effectiveness of black plastic mulch alone and in combination with row covers, on growth and physiological changes of cucumber plants, 6 treatments were established in a randomised complete block design with 4 replications: bare soil (control); black polyethylene mulch alone (B); B plus a clear cover of perforated polyethylene (BRCP); B plus a white cover of perforated polyethylene (BRWP); B plus an Agribon cover of polypropylene (BRA); and B plus a Kimberly farm row cover (BRK). For the plants grown with mulch or mulch combined with row covers, the dry weight of leaves 50 days after seeding (DAS), and the dry weight of whole plants (at 50 and 110 DAS) were significantly (P