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A 2-year field trial was conducted in processing grade potato cv. Kufri Chipsona-3. The treatments comprised recommended dose of fertilizer (RDF) (200:150:150 N:P2O5:K2O kg ha-1) with or without boron (B) application (soil and foliar). The results revealed that B fertilization significantly increased tuber number and yield. Three sprays of 0.1% boric acid (at 40, 50 and 60 days after planting) produced the maximum number and yield of tubers and enhanced B uptake in potato tuber, haulm as well as in total plant accounting 85.8, 182.0 and 169.8% more than control, respectively. The same treatment came up with greatest net return and benefit: cost ratio. B fertilization exerted significant influence on available N and B status of post-harvest soil, while the effect was non-significant on available P and K. Results suggest that right dose and method of B application is vital for optimizing tuber yield and B-use efficiency for processing grade potato. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to study the effect of different planting methods (Happy Seeder sowing, Straw Chopper + Zero Tillage sowing, and conventional sowing) and nitrogen (N) levels (0%, 75%, 100%, and 125% of recommended N) on the emergence, growth, symbiotic parameters, productivity, and profitability of soybean sown after wheat harvest. Growth and symbiotic parameters were significantly better under Happy Seeder sowing and Straw Chopper + Zero Tillage sowing than conventional sowing. The seed yield, nutrient uptake, and economic returns were significantly higher under Happy Seeder sowing than other methods. The growth parameters, symbiotic parameters, biological, straw, and seed yields were increased significantly up to 100% recommended N level. The nutrient uptake increased significantly up to 100% recommended N level. Therefore, sowing with Happy Seeder after combine harvested wheat along with 100% recommended N would best optimize soybean yield and profitability. [ABSTRACT FROM AUTHOR]

The use of optical sensors to detect nitrogen (N) deficiencies and determine in-season fertilizer recommendations has grown. Nitrogen responses are difficult to detect early in the growing season. The objective of this experiment was to determine if different N sources could deliver early season detection of N deficiencies. Four N fertilizer sources were applied at rates of 90 and 180 kg N ha-1 across three site-years. A Greenseeker and SPAD sensor were used to measure in-season fertilizer response index (RI). When differences in sensor RI values between N rates were present, they did not occur until the V9/10 growth stage. No specific N source provided superior results that led to a reliable, early season detection of N deficiency. Reliable differences in response index values could be detected beyond the V7/V8 growth stages. For earlier detection of N responsiveness, and potential N deficiency, other management strategies should be investigated. [ABSTRACT FROM AUTHOR]

Nitrogen (N) application plays an important role in rice production. Limited attention has already been paid to optimizing N fertilizer management strategy for higher grain yield and nitrogen use efficiency (NUE) of rice with crop residue incorporation. Field experiments were conducted with the objective to determine the response of several N application methods to rice production and to evaluate their NUE. Three N fertilizer application methods, i.e., local farmers' N fertilizer practice (FNP), modified farmers' N fertilizer practice (MNP), and increased the amount of N fertilizer practice (INP), were adopted with zero N application as control (CK). The results showed that, compared with that under FNP, grain yield was significantly higher under MFP, owing to signficantly enhanced total spikelets as a result of more panicles per unit area. Relative to FNP, MNP markedly increased nitrogen agronomic efficiency (AEN), nitrogen recovery efficiency (REN), nitrogen physiological efficiency (PEN) and nitrogen partial factor productivity (PFPN), but AEN, PENand PFPNof INP were significantly lower. Further analysis showed that the number of tiller, leaf area index, aboveground biomass, SPAD value, plant N content and N uptake at the early vegetative stage were improved significantly under MNP compared to those under FNP, contributing to higher total aboveground biomass and total N uptake. [ABSTRACT FROM PUBLISHER]

Crop response to manure application may extend beyond the year of application due to residual nutrient availability. A field experiment was conducted to evaluate feedlot manure application (at 0 22.5, 45, 90 and 180 Mg ha−1) and subsequent residual effects (24-yr) on wheat and sorghum grain yields. Sorghum grain yields increased significantly with manure and nitrogen (N) fertilizer application. However, winter wheat grain yield showed no consistent response to manure and fertilizer application in the 9-yr when manure was applied. Averaged across the subsequent 24 years, residual feedlot manure and annual N fertilizer application significantly increased sorghum and winter wheat grain production. Application of cattle manure did increase soil organic matter content, pH and plant available soil nutrients. Our finding showed that growers could take advantage of the long-term benefits of nutrients supplied from manure application to bolster crop production, improve soil quality and reduce fertilizer input cost. [ABSTRACT FROM PUBLISHER]

Fertilization of common bean (Phaseolus vulgaris) plants with amino-acids (AAs) near the beginning of flowering may increase productivity. This procedure is aimed to avoid waste and increase nutrient use efficiency at the end of the crop cycle, improving the leaf area in the translocation of these nutrients to the common bean. In order to test this hypothesis, a field experiment was conducted on a typic Eutrortox (Oxisol) in randomized block design, with three replicates. Four rates of a solution composed of amino-acids (6.8% glycine, 4.4% proline, 3.3% glutamic acid, 2.7% alanine, 1.9% arginine, 1.7% aspartic acid, 1.3% lysine, 1.3% histidine, and 1.0% leucine) applied 45 days after plant emergence were studied. There was no interaction between years of cultivation × amino-acids. However, the productivity of common bean was significantly influenced by the AAs rates, with the highest seed yield obtained at estimated concentration in 0.0094% of the product in foliar sprays. The increases in the rates resulted in increased foliar nitrogen (N) and zinc (Zn) concentrations and decreased sulfur (S) concentration. The macronutrient uptake was nitrogen>potassium>phosphorus>magnesium  >  calcium  >  sulfur (N > K > P >   Mg  >  Ca  >  S),  while  for  micronutrients it was iron>zinc>boron>copper>manganese (Fe > Zn > B > Cu > Mn). In the soil, the concentrations of organic carbon (C) and available P were negatively affected by the AAs rates. [ABSTRACT FROM PUBLISHER]

The present investigation was carried out at CSK Himachal Pradesh Agricultural University, Palampur, Himachal Pradesh, India, during 2009–2011 to economize inorganic phosphorus (P) and enhance profitability of okra (Abelmoschus esculentus)–pea (Pisum sativum) cropping system through arbuscular mycorrhizal fungi (AMF). A field experiment was replicated thrice in a randomized block design comprising 14 treatments involving AMF (Glomus mosseae) at varying inorganic P (50%, 75%, and 100% of recommended soil test-based P dose) and irrigation regimes (40% and 80% available water capacity] in a Himalayan acid Alfisol. In okra, AMF inoculation at varying P and irrigation regimes registered higher P response ratio (PRR), net returns (10–18%), and benefit:cost (B:C) ratio (17–49%) compared to “generalized recommended P dose (GRD)” and their non-AMF counterparts. Similarly in pea, AMF inoculation at varying P and irrigation regimes again registered higher PRR, net returns (14–23%), and B:C ratio (10–58%) compared to GRD and non-AMF counterparts. Higher system productivity (7–16%) and profitability in terms of net returns (9–23%) and B:C ratio (10–54%) were also registered in AMF-imbedded treatments compared to non-AMF counterparts. Further, “AMF + 75% soil test-based P dose” at either of these irrigation regimes registered statistically similar okra–pea system productivity and profitability as that obtained under “100% soil test-based P dose” at either of two irrigation regimes, thus indicating an economy of soil test-based applied P dose by about 25%. Overall, the current study suggests that practice of AMF inoculation has great potential in enhancing system productivity and profitability besides cutting down about 25% inorganic P requirement in okra–pea production system in the Himalayan acid Alfisol. [ABSTRACT FROM AUTHOR]

Hydroponic and field experiments were conducted to assess the optimum nitrogen (N) levels in strawberry leaves for the appropriate management of its N nutrition under field or protected cultivation. Unlike the common view that leaf petiole is the right plant organ to sample for strawberries, the study showed that the leaf blade, of the most recently fully expanded leaf, is more responsive and therefore a better indicator of the N supply changes in the strawberry plant. This was attributed to the distinctive characteristic of strawberry plants to accumulate high concentrations of nitrates in leaf blades when there is luxury consumption of N. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to study the effect of humic acid multinutrient fertilizers like Grow Flow 45H and HA-NPK complex on crop yield, nutrient content and uptake, and nutrient use efficiency of potato. Application of Grow Flow 45H (humic acid multinutrient liquid fertilizer) at recommended dose increased the tuber yield by 9.3% as compared to chemical fertilizer. Nitrogen (N), phosphorus (P) and potassium (K) content of the Grow Flow 45H treated plants were 2.89, 0.33 and 1.58% in shoots and 1.89, 0.21 and 1.03% in tubers, respectively which were significantly higher than the other treatments. Grow Flow 45H increased the N, P and K use efficiencies by 16.4%, 9.3% and 18.3% respectively over chemical fertilizer. Though HA-NPK complex fertilizer (developed in the laboratory) was not significantly different from chemical fertilizer in respect of yield, the contents and uptake, and use efficiencies of N, P and K; however the former was found better than the latter. [ABSTRACT FROM AUTHOR]

A field experiment entitled “nitrogen and vermicompost interaction on soil and leaf nutrient status of kinnow mandarin in vertisols of Jhalawar district” was conducted at the Fruit Research Farm, Department of Fruit Science, College of Horticulture and Forestry, Jhalawar (Rajasthan) during 2012–13 to study the effect of different levels of nitrogen and vermicompost on physico-chemical properties of soil and leaf micro and macro nutrient contents of Kinnow mandarin. The result indicated that application of T15treatment i.e. nitrogen at 350 g/plant + vermicompost 20 kg/plant was found best with regard to improvement in soil physico-chemical properties like organic carbon content (0.44%), available nitrogen (N) (379.36 kgha−1), available phosphorus (P) (25.56 kgha−1), available potassium (393.29 kgha−1) and reduces electrical conductivity (0.34 dSm−1), soil pH (7.42) and calcium carbonate (CaCO3) content percentage (15.20) of soil. [ABSTRACT FROM AUTHOR]

To evaluate the nitrogen (N) use efficiency of rice plants applied with enhanced panicle N fertilization (PN) on different planting patterns, field experiments were carried out with 5 nitrogen managements (two PN levels combined with two total N levels, and check, CK) under transplanting (TP) and direct seeded (DS). Our result showed that nitrogen use efficiency traits of physiological efficiency (PE), nitrogen use efficiency for grain (NUEg), and recovery efficiency (RE) of DS rice were decreased compared with TP rice, and total nitrogen accumulation (TN+N) were kept consistent between TP and DS. However, PN × PT interaction effect was significant in partial factor productive of applied N (PEP), agronomic efficiency (AE), nitrogen harvest index (NHI) and nitrogen translocation rate (NTR). High PN improved the AE value in DS system, but showed little effect in TP system. Oppositely, high PN decreased the PEP in TP system, while showed little effect in DS rice. The results indicated that improved PN applied in the TP system might affect the farmer's benefits without improving plant nitrogen utilization. For DS rice, though PEP was not significantly improved, but the N utilization efficiency of fertilizer uptake was enhanced. Furthermore, PE, AE, PEP, and NUEg, which were related to the performance of yield production, were significantly correlated with each other with P value <0.01. RE was correlated with all traits but NTR and NUEgwithPvalue <0.01. NTR was correlated with NHI and NUEgwithP<0.01. Results showed that NUEgwas significantly correlated with PE, AE, PEP, and NTR. Considering most of the agronomic practice was carried out without zero N control, NUEg might be a practical option for farmers to evaluate the plant N fertilizer physiological use efficiency when soil texture is similar. [ABSTRACT FROM PUBLISHER]

A hydroponic experiment was conducted to study the effects of fertilization with different nitrate/glycine (Gly) ratios on spinach growth and composition of amino acids. Results showed partly replacing nitrate (NO3−) by Gly supplied both nitrogen and carbon nutrition for spinach. Spinach accumulated the equal biomass. Total nitrogen (N) in plant had a positive relationship with nitrate/Gly ratios in nutrition. There was more than 2-fold increase in N uptake from all glycine to nitrate, and plant nitrate contents increased from 0.97 to 3.13 mg g−1. All of 17 proteogenic amino acids in mature leaves exhibited a similar trend, the content in leaf tissue increased with an increasing ratio of nitrate/Gly, whereas relative change rate differed for each individual amino acid. In principal component analysis (PCA), the first component accounted for 80.5% of the total variance, and the N treatment appeared to be separated by this factor. In self-organizing map (SOM), 17 amino acids were divided into three clusters according to responds to nitrate/Gly ratios. [ABSTRACT FROM AUTHOR]

Field experiments were conducted over 2 years with the hypothesis that farmyard manure (FYM), soybean residue (SR) as sole and/or in combination with urea under different tillage practices has similar effects on crop nitrogen (N) status and accumulation of dry matter (DM). Conventional ploughed plots had higher DM than other. Post anthesis accumulation of DM for minimum tillage (MT) was 4% higher than DT. Incorporation of 20 tons FYM ha−1combined with 30 or 60 kg ha−1had higher DM and N partitioned to leaves, stem, and spike than control. Leaves accumulated more DM at anthesis stage than other, whereas stem and spike at maturity than earlier stages. Fertilized plots had higher DM and N redistribution efficiency than control. However, N remobilization increased linearly with increasing DM accumulation (r2= 22%). It was concluded that FYM coupled with N under MT showed marked variations for DM partition and N status in wheat than other treatments. [ABSTRACT FROM AUTHOR]

A field experiment was conducted at farmer's field in Mollisols ofTaraisoils in Uttarakhand (India), to assess the direct and residual effect of sulfur fertilization in wheat-soybean cropping sequence. Four levels of sulfur (S; 0, 15, 30, and 45 kg ha−1) were applied to main crop (wheat) along with recommended dose of nitrogen (N), phosphorous (P), and potassium (K). The direct and residual effect of sulfur at highest level showed 27 and 6 percent increase in grain yield of wheat and soybean over control, respectively. The increase in grain yield of wheat was significant at each sulfur level. The direct as well as residual effect of sulfur showed significant increase in sulfur concentration and its uptake by grain and straw except increase in sulfur concentration and uptake by soybean straw. In wheat-soybean cropping sequence, the agronomic efficiency and apparent sulfur recovery decreased with increase in levels of sulfur, but the percent response increased with increasing sulfur application. Different forms of sulfur such as total sulfur, organic sulfur, calcium chloride extractable sulfur, potassium dihydrogen phosphate extractable sulfur, and non-sulfate sulfur in post-harvest soil increased according to sulfur level applied but it decreased under control and also after residual crops. The buildup of sulfur in surface soils was greater than in the deeper soils. Application of sulfur showed the positive sulfur balance and it increased with increase in sulfur level, while it was negative under control. A major portion (46–62%) of applied sulfur contributed to increase in sulfur content of root zone soil followed by unaccounted component (25–40%) and small portion (11–18%) was absorbed by wheat plant as uptake. [ABSTRACT FROM AUTHOR]

A three-year field experiment was carried out to study the effects of green manure application on the soil microbial biomass carbon, nitrogen and soil enzyme activities in order to provide a theoretical basis on low-carbon agriculture, environment-friendly agriculture and promote the sustainable development of tobacco production. Six treatments were set and were: check (CK) (contrast, no application of green manure), T1 (application of ryegrass only 1 year), T2 (application of ryegrass 2 years), T3 (application of oats 2 years), T4 (application of ryegrass 3 years), and T5 (application of oats 3 years), which was based on continuous planting oats and ryegrass(Lolium multiflorum L.)in our experiment. The results showed that soil microbial biomass carbon, nitrogen, and the activity of soil urease, acid phosphatase (ACP), sucrase, and catalase increased with each year and with the application of green manure. Compared with the control, after the application of green manure the content of soil microbial biomass carbon and nitrogen increased 1.94%–93.07% and 2.30%–145.07%, respectively, and the activity of soil urease, ACP, sucrase, and catalase increased 1.45%–56.52%, 2.34%–33.17%, 0.96%–172.66%, and 3.33%–85.71%, respectively. Correlation analysis indicated that soil microbial biomass carbon and soil enzymes activity had certain relevance that showed the dynamic process of soil microbial biomass and enzyme activity were coordinate with the decomposition process of green manure and the absorption of mine nutritional to tobacco plant. The results demonstrate that continuous application of green manure could increase soil biological fertility level. [ABSTRACT FROM AUTHOR]

Soybean [Glycine max(L.) Merr.] shoot nitrogen (N) traits are important for seed production and may hold potential for improving seed yield and quality. Field experiments were established to survey shoot N traits in i) plant introductions, ii) a recombinant inbred line (RIL) population, and iii) modern cultivars. A wide range of N concentrations was observed at beginning seed fill for leaves, petioles, and stems and at maturity for stems. Significant genotypic variations in stem N traits were found in modern cultivars and the RIL population. Molecular marker analysis identified multiple loci associated with stem N concentration. Significant relationships between various tissue N traits and seed yield and quality were also observed. These results illustrate the importance of N dynamics in vegetative tissues for soybean yield and seed composition. The observed variation in N traits indicates that selecting for vegetative N traits could potentially increase yield and improve seed quality. [ABSTRACT FROM AUTHOR]

Dry bean is an important legume crop for Latin American people and nitrogen is one of the most yields limiting nutrients for bean crop. A greenhouse experiment was conducted to evaluate nitrogen (N) use efficiency of 20 dry bean genotypes. Genotypes were grown on an Oxisol and two N levels used were without N application (low level) and an application of 400 mg N kg−1(high level). Shoot dry weight, grain yield and yield components, N concentration and uptake in shoot and grain were significantly affected by N and genotype treatments. Grain yield had a highly significant (P< 0.01) association with shoot dry weight, pod number, grains per pod and 100 grain weight. Among the 20 genotypes tested, Perola, CNFR 7847, CNFR 7865, CNFP 7777 and CNFM 6911 were found to produce reasonably good yield at low N rate as well as responded well to applied N. Whereas, some genotypes like BRS Radiante, CNFP 7624, CNFM 7875, CNFM 7886, CNFC 7813, CNFC 7827, CNFP 7677 and CNFP 7775 produced very good yields at higher N rate but very low yields at lower N rate. Hence, these genotypes are good for farmers using higher technology. Nitrogen concentration and uptake were higher in dry bean grains compared with shoot and 63% of N accumulated at zero N rate and 75% N accumulated at 400 mg N rate were translocated to grain across 20 genotypes. Nitrogen uptake efficiencies were having highly significant (P< 0.01) quadratic relationship with grain yield. This indicates that improving N uptake in dry bean plants can increase grain yield. [ABSTRACT FROM AUTHOR]

A long-term field experiment with rice-wheat cropping was started in the wet season of 1988 with four levels of lantana (Lantana camaraL.) (0, 10, 20, and 30 Mg ha−1on fresh weight basis) and three tillage practices (No puddling, puddling, and soil compaction). From wet season of 1997, however, three tillage practices were replaced with three levels of nitrogen (N) and potassium (K) to rice (33, 66, and 100% of recommended) and 66% of recommended N, phosphorus (P), and K to wheat. Phosphorus was totally omitted for the rice crop. The recommended N and K for rice was 90 and 40 kg ha−1, whereas the recommendations for N, P, and K for wheat were 120, 90 and 30 kg ha−1. Organic amendments are known to improve soil productivity under rice-wheat cropping by improving physical conditions and nutrient status of the soil, but their availability is restricted. There is a need to identify locally available and cost-effective organic materials that have minimal alternate uses as fodder and fuel. We evaluatedLantana camaraL. residues, a fast-growing weed in nearby wastelands, as a potential soil organic amendment. Among the different fractions of K, nonexchangeable K was dominant followed by exchangeable and water soluble K. The incorporation of lantana (10 to 30 Mg ha−1) over the last 12 years has resulted in a significant build-up of all the K fractions, the maximum being in water-soluble K (10 to 32%) followed by exchangeable K (18 to 27%) and least in nonexchangeable K (5 to 7%) over no lantana incorporation. The increasing levels of these two inputs significantly and consistently increased ammonium acetate (NH4OAc)- extracted K (available K) content in soil and also resulted in significantly higher accumulation of K by the crops during the years of experimentation. Among different K fractions, exchangeable K was observed to be the most important K fraction contributing towards wheat and rice yields as well as K accumulation by wheat and rice. Stepwise multiple regression equations indicated that exchangeable K was the most important variable contributing towards total variation in grain yield and K accumulation by wheat or rice. [ABSTRACT FROM PUBLISHER]

Plants require nutrients including nitrogen (N), phosphorus (P), and potassium (K) for their growth and production. Although there have been previously extensive research work regarding the effects of NPK on plant growth, data related to the effects of long term application of NPK on the quality and quantity of citrus under rainfed and irrigated conditions are little. Accordingly, such effects were evaluated in this research work using different chemical fertilization factorially combined and on the basis of a completely randomized block design. Using ammonium sulfate (100, 150 and 200 g tree−1), triple super phosphate (0, 25, 50, and 75 g tree−1) and potassium sulfate (0, 50, 100, 150 g tree−1) the quantity and quality of citrus fruit, variety Thomson were determined in a 10-year experiment in two different research stations in Ramsar, Iran. NPK fertilization significantly affected the quality and quantity of citrus fruits, indicating the significance of NPK fertilization for citrus production. [ABSTRACT FROM PUBLISHER]

Evaluation of source or sink limitations on maize (Zea maysL.) yield and yield components is important for the rational design of agricultural practices as well as breeding strategies. There is little information on how the source or sink limitations during the effective grain-filling period affect final kernel quality. The objective of this study was to evaluate the effect of source/sink manipulation in different times after mid-silking stage on kernel weight (KW), kernel number per square meter (KN m−2), kernel protein and oil of different maize hybrids. Field experiments were conducted at the experimental field of College of Agriculture, Shiraz University, Shiraz, Iran, located at Bajgah (52° 35′ N and 39° 4′ E and 1810 m above sea level, asl) during the 2008 and 2009 growing seasons. The treatments included three hybrids and defoliation that were arranged in the main, and subplots, respectively. Leaves removal treatments were imposed when plants were at the mid-silking stage. Silking was taken as the time when 50% of the plants in a row presented visible silks. Defoliations included control, 50% of defoliation at 25 (early defoliation), and 35 (late defoliation) days after silking (defoliation treatments were applied to all plants of each plot). The experiments were conducted in randomized complete block (RCB) design with three replications and the treatments in a split-plot arrangement. Early defoliation greatly reduced kernel growth rate and grain filling period, resulting in lower mean kernel weight. Defoliation treatments modified KN m−2and kernel number per ear (KNPE) and variations in these components affected protein and oil content. Decreased source size by defoliation decreased kernel protein content dramatically with no significant change in oil content. Differences among treatments appeared to be related only to the post-flowering source/sink ratio. Therefore, to improve protein yield in maize, hybrids and agronomic practices should aim to increase the post-flowering source/sink ratio. [ABSTRACT FROM PUBLISHER]

Field experiments were conducted for two years to compare and identify bread spring wheat (Triticum aestivumL.) genotypes which make the most efficient use of nitrogen (N). Such information is required for breeding strategies to reverse the negative relationship between yield and protein content. Three Swiss spring wheat cultivars (‘Albis’, ‘Toronit’, ‘Pizol’) and an experimental line (‘L94491’) were grown without (N0; 0 kg N ha−1) and with high fertilizer N [(NH4NO3); (N1; 250 kg N ha−1) supply on a clay loam soil with low organic matter content. Biomass and nitrogen accumulation in biomass as well as the leaf growth and senescence patterns (SPAD) were investigated in an attempt to explain the physiology of growth and N translocation of these genotypes. The pre-anthesis accumulation of biomass and N in the biomass depended on genotype only at N1 in 2000. In this year, conditions were less favorable for the pre-anthesis accumulation of biomass and N, which was, on average, 10 and 20% lower, respectively, of the total than in 1999. The contribution of pre-anthesis assimilates to the grain yield (CPAY) was higher in 1999 for all genotypes (36.9%) compared to 2000 (13.5%) except ‘Toronit’. Between anthesis and maturity the climate influenced the genetic variability of some N use efficiency components: N translocation efficiency (NTE) and dry matter translocation efficiency (DMTE). NTE was higher in 1999 (68.1%) compared to 2000 (50.7%); 1999 was a year in which the post-anthesis period was drier and warmer than usual. ‘Toronit’ produced the highest biomass by maturity due mainly to greater and longer lasting green leaf area after anthesis. ‘Albis’ performed relatively well under low input conditions, with considerable amounts of N being re-translocated to the seeds at maturity (NHI), whereas ‘Pizol’ accumulated in grains N as high as for ‘L94491’. In a humid temperate climate breeding for greater N uptake and partitioning efficiency may be a promising way to minimize N losses and produce high phytomass and grain yields. Using high protein lines as selection material and combining them with high biomass genotypes may lead to high protein contents without decreasing yield. [ABSTRACT FROM PUBLISHER]

The interactive effect of potassium (K) and sulfur (S) fertilization on productivity and mineral nutrition of sunnhemp (Crotalaria junceaL.) was evaluated in a field experiment during 2008 and 2009 cropping seasons at Uttar Pradesh, India. Potassium and sulfur fertilizers increased fiber yield and nutrient uptake of sunnhemp. It was observed that an application of K and S at 40 kg ha−1each significantly increased the total dry matter, fiber yield, and nutrient uptake of sunnhemp. The crop yield response to the added S was greater than for K and the nutrient use efficiency was also higher at lower levels of fertilizer addition. The increased levels of K and S improved the number of nodules and crude protein content of sunnhemp leaves. [ABSTRACT FROM PUBLISHER]

A long-term field experiment (1998 to 2010) investigated the effects of vermicompost (VC) and chemical fertilizers (CF) application alone or in combination on biomass partitioning, nutrient uptake and productivity of arecanut. Trunk biomass (kg palm−1) was significantly higher with integrated treatments (40.8–43.0) than control (23.9). Biomass partitioning to kernel varied between 4.6% in control to 7.7% in CF 100 and 200% nitrogen (N)- phosphorus (P)- potassium (K). The leaf P and K content varied significantly among treatments. The N immobilized in trunk (g palm−1) was significantly higher in integrated treatments (119-127) than in control (93). Phosphorus and K uptake by trunk followed same trend. The leaf K uptake and total K removed were found significant. The nutrition treatments registered significantly higher kernel yield (2508–3176 kg ha−1) than control (1721 kg ha−1). The increased yield of arecanut from chemical fertilizers (73–85%) was more pronounced when compared to VC (48–59%) and integrated treatments (46–63%) over control. [ABSTRACT FROM AUTHOR]

A field experiment conducted on rapeseed (Brassica juncea L.) during 2005–2006 in a typical lateritic soil (Alfisol) of West Bengal, India revealed that sources of sulfur viz. gypsum and magnesium sulfate and levels of sulfur (0, 20, 40, 60 kg S ha−1) have significant influence on grain yield, total biological yield, sulfur concentration in grain and stover, total sulfur uptake, oil content and oil yield and chlorophyll content. The maximum grain yield (18.28 q ha−1) and oil yield (8.59 q ha−1) was obtained with magnesium sulfate followed by gypsum yielded the grain yield of 17.99 q ha−1 and oil yield of 8.22 q ha−1 at 40 kg S ha−1. Overall, the best performance was recorded when sulfur was applied at 40 kg S ha−1 either as magnesium sulfate or gypsum. Results revealed that magnesium sulfate may be considered as the better source of sulfur than gypsum to raise the mustard crop in sulfur deficient acidic red and lateritic soils of West Bengal and if farmers apply either magnesium sulfate or gypsum to soils, the possible deficiency of sulfur and magnesium/calcium in soils and plants can be avoided. [ABSTRACT FROM AUTHOR]

The objective of the study carried out in the Upper Oueme Catchment in Benin (West Africa) was to assess the nutrient status in yam (Dioscorea rotundata) through the Diagnostic and Recommendation Integrated System (DRIS), to compare yield, foliar nutrient concentrations and the variance of nutrients of low-and high-yielding groups. Field experiments were carried out in 2001 and 2002 using a randomized complete block design with four treatments, 2001: n = 80, 2002: n = 109) at three sites: Beterou, Dogue, and Wewe. Nitrogen (N), followed by potassium (K), phosphorus (P), and magnesium (Mg) were identified as the most limiting nutrients in 2001 whereas sulfur (S) followed by N was identified as most limiting ones in 2002. Imbalanced nutrition was observed in both the years but was higher in 2001 compared in 2002. They may be utilized as a basis for calibrating the fertilization program of yam. [ABSTRACT FROM AUTHOR]

We evaluated the effectiveness of soil and foliar applications of calcium chloride (CaCl2) on reducing pear susceptibility of brown spot (Stemphylium vesicarium). Two experiments were done using pear trees of the variety Abbé Fetel grafted on quince (Cydonia oblonga) rootstock. Potted trees were treated with soil and foliar application of CaCl2, while commercial trees were subjected only to soil application of 5.6 g CaCl2 L−1, and 11.2 g CaCl2 L−1. In a controlled environment, leaf and fruit brown spot incidence decreased with the increase of residual calcium (Ca) concentration in the tissue, according to a second degree function. In fruits from field experiment, disease symptoms were decreased by soil application of CaCl2 that increased Ca fruit concentration above 1000 mg kg−1 dw; however, no clear correlation between fruit Ca and brown spot incidence was found. Leaf water and osmotic potential were not related to brown spot incidence. [ABSTRACT FROM PUBLISHER]

A greenhouse experiment was carried out to evaluate chromium (Cr) toxicity in urograndis (Eucalyptus urophylla S. T. Blake x grandis W. Hill ex. Maiden). Chromium nitrate was amended to Clark's nutrient solution (0.00, 0.04, 0.08, 0.16, 0.32 and 0.64 mmol L−1 Cr), which was used to breed one urograndis cutting per pot (four replications). Regression analysis revealed that Cr rates of 0.08 mmol L−1 or higher significantly decreased (P < 0.01) dry matter yield of shoot and root. Chromium accumulation order in plant was: root > stem > leaves. Critical Cr toxicity level in leaves was 0.74 mg kg−1. Uptake and translocation of nutrients were affected differently by Cr. Mostly have their uptake reduced due to root damage. Magnesium, iron and manganese translocation increases, supposedly to maintain normal photosynthetic activity. Wilting is the main visual symptom of Cr toxicity. Urograndis may be suitable for contaminated sites phytostabilization and receive industrial waste fertilization. [ABSTRACT FROM AUTHOR]

The study was conducted at three sites during 2008 and 2009 in the North-East China Plain (NECP). Field experiments consisted of five or six nitrogen (N) fertilization rates (0–350 kg N ha−1). Shoot biomass and N concentration (Nc) of spring maize (Zea mays L.) were determined on six sampling dates during the growing season. Nitrogen application rate had a significant effect on aerial biomass accumulation and Nc. As expected, shoot Nc declined during the growing period. A critical N dilution curve (Nc = 36.5 W −0.48) was determined in China, which was a little different from those reported for maize in France and Germany. Besides, the N nutrition index (NNI) calculated from this critical N dilution curve was significantly related to relative grain yield, which can be expressed by a linear with plateau model (R2 = 0.66; P < 0.001). NNI can be used as a reliable indicator of the level of N deficiency during the growing season of maize. [ABSTRACT FROM AUTHOR]

A series of greenhouse and field experiments were conducted at Northwest Frontier Province (NWFP) Agricultural University, Peshawar, Pakistan to study the effect of seed priming with dilute solutions of phosphorus (P) on seedling growth and nutrient uptake of mungbean (Vigna radiata L.). Seed of mungbean cv. ‘NM-92’ were primed in 0.01% and 0.02% P solutions and also in water for four hours along with a non-primed seed (control). The primed seed was washed with distilled water to remove nutrients adhering to seed coat and air dried. The amount of nutrients introgressed into seed or adhered onto the seed hull was measured. Higher P was introgressed by the seed primed with 0.02% P solution followed by seed primed in 0.01% P solution as compared to water soaked and dry seeds both in nonwashed and surface washed seeds. Likewise, seed priming with P solutions significantly improved seedling P concentration and uptake 14 and 21 days after sowing as compared to water soaked and dry seeds in both greenhouse and field experiments. Similarly, seed priming with P solutions significantly improved fresh and dry weight and plant height of mungbean seedlings 21 days after sowing in the field experiment. [ABSTRACT FROM PUBLISHER]

Among the major nutrients, potassium (K) not only improves yields but also improves quality parameters. Field experiments were conducted to assess the comparative effect of sources and rates of K fertilizer on potato yield and quality on a sandy loam soil. Graded doses of potassium, i.e., 0, 150 and 225 kg ha−1 K2O from sulfate and muriate of potash were applied in triplicate. Recommended dose of nitrogen (N) and phosphorus (P) applied uniformly. Significant increase in tuber yield was observed with 150 kg ha−1 K2O from both the sources over control. Increase in tuber yield with 225 kg ha−1 K2O was statistically non significant compared to 150 kg ha−1. The dry matter and specific gravity were more affected with sulfate of potash (SOP) than muriate of potash (MOP). The quality parameters like dry matter, specific gravity, starch contents, vitamin C, chips color and taste were improved with K application. [ABSTRACT FROM AUTHOR]

Impact of integrated nutrient and crop residue management on crop productivity, phosphorus (P) uptake and apparent P balances was investigated in a 5-year field experiment on two calcareous soils, i.e., Awagat (coarse loamy) and Shahpur (fine silty) in cotton-wheat sequence. Minimum mean P uptake (kg ha−1) by cotton with Farmers’ Fertilizer Use (FFU) treatment was 8.89 in Awagat and 11.54 in Shahpur soil. Corresponding maximum mean P uptake was 15.30 and 17.01 kg ha−1 with Integrated Nutrient Management (INM), respectively. Nutrient treatments effect on P uptake by wheat was similar to cotton. Phosphorus uptake was further enhanced by crop residue recycling. Phosphorus uptake trend by cotton was negative under FFU without residue recycling and was positive with residue recycling. While P uptake trends were positive under all other treatments. INM yielded positive apparent P balances (kg ha−1) of 56–306 in Awagat and 24–288 in Shahpur soil. [ABSTRACT FROM PUBLISHER]

This work aimed to study whether soil plant analysis development (SPAD) and its modifications (SPAD/SLA, SPAD/N) were sensitive indicators of intra-seasonal nitrogen (N) changes in the soil-root-petiole-leaf continuum in sugar beets. In a three-year, field experiment, 11 occasions of measurement per year took place. Significant intra-seasonal changes of soil [total N, nitrate (NO3)-N], root (α-amino N), petiole (NO3-N) and leaf [SPAD,%N, SLA, SPAD/N, SPAD/SLA, specific leaf nitrogen (SLN)] traits were found. SPAD readings failed to predict N status changes in soil and sugar beets. SPAD modifications (SPAD/SLA, SPAD/N) gave significant correlations with root α-amino N (r = −0.80, P < 0.001, n = 33) and petiole NO3-N (r = −0.53, P < 0.01, n = 33) which are considered as sugar beet N status indicators. SPAD readings adjusted for intra-seasonal, leaf ontogenetic changes as they captured by SLA improved the correlations with the indicators of sugar beet N status and especially with root α-amino N. Also, SPAD/SLA gave a significantly correlation with leaf %N (r = −0.82, P < 0.001, n = 33). [ABSTRACT FROM PUBLISHER]

A field experiment on the response of mungbean (Vigna radiata L. Wilczek) to tillage systems (reduced and conventional) and phosphorus management under rainfed condition was conducted at New Developmental Farm of NWFP Agricultural University, Peshawar during summer 2005. Combined analysis of the data indicated that reduced tillage produced higher number of branches (3.8), pods plant−1 (17), number of grains pod−1 (9.0), 1000 grain weight (47.34 g), while higher plants m−2 (31), biological yield (2992 kg ha−1) and grain yields (663 kg ha−1) and number of plants at harvest (281200 ha−1) were obtained from conventional tillage system. Phosphorus applied at the rate of 40 kg P2O5 ha−1 significantly increased plant heights (57 cm), number of branches (4.1) and pods plant−1 (19), number of grains pod−1 (10), 1000 grain weight (48.42 g), biological (3197 kg ha−1) and grain yields (684 kg ha−1). Placement application method of phosphorus had significantly greater number of branches plant−1 (3.8), number of pods plant−1 (17), and number of grains pod−1 (9.0), 1000 grain weight (47.39 g), biological (2797 kg ha−1) and grain yield (610 kg ha−1), respectively. The interaction between tillage (T) and method of application (M) showed that highest number of pods plant−1 (18), and number of branches plant−1 (3.9) were recorded in plots of reduced tillage system in which placement method of P2O5 application was used. The interaction between methods of application (M) and P levels showed that greater number of pods (20), biological (3368 kg ha−1), and grain yield (718 kg ha−1) were obtained when 40 kg P2O5 ha−1 was applied by placement application method. [ABSTRACT FROM PUBLISHER]

A field study was conducted at the Research Farm of NWFP, Agricultural University, Pakistan. Chickpea (Cicer aeritinum L.) cultivar, ‘Hassan-2000’, was sown as a winter crop under conventional tillage (CT) or no-tillage (NT) dryland systems in a randomized complete block design with split plot arrangement using four replications. Three levels of phosphorus (P; 0, 80 and 120 kg P2O5 ha−1) were broadcast applied at the time of last plowing and were thoroughly mixed in subplot size of 1.8 × 5 m. About 20% less weed biomass and 2% higher grain yield was recorded under CT than in NT. Plots supplied with P2O5 had higher value of the all the parameters under study except number of plant m−2 when compared with control (no P applied). However, the grain yield response to P beyond 80 kg ha−1 was not positive. CT + 80 kg P2O5 ha−1 was identified as the optimum level for maximum chickpea production under the existing dryland condition where application of herbicides in NT is not possible. Further experiments to study the optimization of P in chickpea production under dryland conditions are required. [ABSTRACT FROM PUBLISHER]

Field experiments were conducted to evaluate the effect of foliar spray of soluble silicic acid on growth and yield parameters of wetland rice. The results revealed a significant effect on achieving higher grain and straw yield with foliar silicic acid over control. Foliar spray of silicic acid at 2 and 4 ml L−1 increased the grain and straw yield and application of 8 ml L−1 decreased the yield. Foliar spray of silicic acid at 4 ml L−1 along with half dose of recommended pesticide effectively increased the yields over all other treatments. The content and uptake of silicon in grain and straw was recorded higher with the foliar spray of silicic acid over control. This investigation concludes that application of silicic acid at 4 ml L−1 along with half dose of recommended pesticide as foliar spray increased the grain and straw yield, besides Si content and its uptake over control. [ABSTRACT FROM AUTHOR]

The tolerance of different coffee-plant progenies to zinc (Zn) deficiency was studied in a green house experiment arranged in a completely randomized design, in a 14 × 2 factorial scheme (14 progenies and two Zn concentrations), with four replications. Coffee-plant seedlings were grown for ten months in nutritive solution with or without Zn. There were evaluated for growth characteristics, zinc concentrations, and zinc requirement. The grouping involving growth characteristics allowed discriminating the progeny ‘UFV 4066-3’ as highly zinc-demanding and ‘IAC 4376-5’ as low zinc-demanding. The data on plant dry matter and zinc accumulation showed that the progenies ‘IAC 4376-5’ and ‘UFV 4066-5’ had low zinc requirement when ‘Caturra Amarelo 1’, ‘UFV 4066-3’, ‘Caturra Amarelo 2’ and ‘Caturra Vermelho 2’ had high zinc requirement. Leaf area reduction (%), leaf number, active zinc content in completely expanded leaves and total zinc in roots were the variables of highest relative importance in discriminating coffee plant progenies. [ABSTRACT FROM AUTHOR]

Field experiments with boron (B) (0, 1, 3, 6, and 9 kg ha−1 B) were conducted in 2005 and 2006 to determine the optimum economic B rate (OEBR). Critical soil test and tissue B values for grain yield (GY) and total yield (TY) production for ‘Krik’ cv. and ‘Bezostiya’ cv. grown on B-deficient calcareous Aridisols in Eastern Turkey were determined. Averaged over the two years, ‘Krik’ and ‘Bezostiya’ cvs., the OEBR was 6.4–5.6 kg B ha−1 with an average GY yield of 2.0–3.8 Mg ha−1, and 5.9–5.6 kg B ha−1 with an average TY yield of 5.5.0–10.8 Mg ha−1, respectively. The average soil B content at the OEBR was 1.15–0.92 mg kg−1 while leaf tissue B content amounted to 24.0 and 30.3 mg kg−1 for ‘Krik’ and ‘Bezostiya’ cvs., respectively. Boron application decreased tissue calcium (Ca), and magnesium (Mg), and increased tissue nitrogen (N), phosphorus (P), potassium (K), zinc (Zn), iron (Fe), copper (Cu) and manganese (Mn). [ABSTRACT FROM AUTHOR]

Since the early 1990s canola (oilseed rape, Brassica napus L.) has become a major crop species grown on the predominantly sandy soils of southwestern Australia. Numerous studies have been undertaken to determine the fertilizer requirements of the crop in the region. This paper reports results of a field experiment conducted at three sites on typical acidified (pH [Ca] ∼4.6) sandy gravel soils to identify if molybdenum (Mo), manganese (Mn) or boron (B) were deficient for canola grain production. Different levels of each element, separately or as mixtures, were applied as foliar sprays at mid-flowering. Maximum grain yield responses of ∼11-20% to applied Mo, as sodium molybdate (39% Mo), were obtained when 40 g Mo/ha was applied. Maximum grain yield responses of ∼13-28% to applied Mn were achieved by applying 1000 g ha-1 Mn, as manganese sulfate (24% Mn). A mixture of 40 g Mo ha-1 and 1000 g Mn ha-1 increased grain yields by ∼15-38%. Boron, applied as borax (11% B), sprayed individually or in combination with Mo or/and Mn, had no effect on grain yields. None of the foliar spray treatments had any effect on oil concentration in canola grain. The sprays did not cause any visible damage to foliage. Soil acidification has been shown to induce Mo deficiency for cereal crops in the region and both soil acidification and induced Mo deficiency are alleviated by applying sufficient lime to raise pH of top 10 cm soil to 5.5 or greater, and this strategy should also apply to canola. Further research is required to determine the fertilizer Mn requirements for canola grain production in the region. [ABSTRACT FROM AUTHOR]

Improper sulfur (S) and potassium (K) fertilizer management, particularly with continued soil nutrient mining, is one of the major factors contributing to low seed yield of canola in northwestern Pakistan. A field experiment was conducted in 2007-2008 on a S and K deficient clay loam soil at the Research Farm of NWFP (Northwest Frontier Province) Agricultural University, Peshawar, Pakistan, with an objective to determine seed yield and yield components response of Brassica oilseed rape versus mustard to S and K application. Twenty treatments in a randomized complete block design were consisted of two oilseed rape (B. napus canola) and mustard (B. juncea canola) genotypes at three rates each of S (15, 30, and 45 kg S ha-1) and K (30, 60, and 90 kg K ha-1) fertilizers plus one control (no S and K applied). Seed yield and yield components increased significantly with K and S fertilization as compared to the zero-S/zero-K control. Both genotypes responded positively for seed yield and yield components to K and S fertilization, but the magnitude of response varied with levels of S and K, as well as combined K + S applications. It is concluded that a combination of 60 kg K + 30 kg S ha-1 would improve seed yield and yield components of rape and mustard in the study area and contribute significantly to increased production. Growing B. napus was better than B. juncea in the study area, because B. napus produced significantly higher seed yield and yield components than B. juncea, indicating that yield components are the most important criteria for selection of Brassica genotypes for higher seed yield. [ABSTRACT FROM AUTHOR]

Lowland rice is a staple food for more than 50% of the world's population and phosphorus (P) deficiency is one of the main constraints in rice production in tropical lowlands. A field experiment was conducted for two years consecutive with the objective to evaluate 12 lowland rice genotypes for P use efficiency. The P rates used were 0, 22, 44, 66, and 88 kg P ha-1 (0, 50, 100, 150 and 200 kg P2O5 ha-1) applied to an Inceptisol. The genotypes used were BRS Jacana, CNAi 8860, BRS Fronteira, CNAi 8879, CNAi 8880, CNAi 8886, CNAi 8885, CNAi 8569, BRSGO Guara, BRS Alvorada, BRS Jaburu and BRS Bigua. There were significant and quadratic responses of genotypes to phosphorus fertilization. Adequate P rates for maximum grain yield varied from genotype to genotype. However, across 12 genotypes, maximum grain yield was obtained with the application of 54 kg P ha-1. Genotype BRS Jacana was most efficient and genotype CNAi 8569 was most inefficient in P use efficiency. Shoot dry weight and panicle number was also increased significantly and quadratically with increasing P rates in the range of 0 to 88 kg P ha-1. These two plant parameters were positively associated with grain yield. Agronomic efficiency (kg grain produced per kg P applied) was significantly decreased with increasing P rates in the range of 22 to 88 kg P ha-1. [ABSTRACT FROM AUTHOR]

Nitrification and ammonia volatility are two important impediments to nitrogen (N) use efficiency and crop uptake around the world. Nutrisphere® is a relatively new product whose manufacturer claims both nitrification and urea volatilization inhibiting properties. Urea coated with Nutrisphere is and the resulting fertilizer is called Nutrisphere®-N urea, or Nutrisphere-N (NSN). Eight field studies on spring (Triticum aestivum L.) or durum [T. turgidum L. subsp duram (Desf.) Husn.] wheat in North Dakota, three field studies in Mississippi/Arkansas on rice (Oryza sativa L.), four laboratory experiments in North Dakota and one in Arkansas were conducted to determine the nitrification and urea volatilization inhibiting ability of NSN compared with urea alone. Results of field and laboratory experiments revealed that the product has no nitrification or urea volatilization inhibiting properties at the recommended rates and spring wheat and rice did not benefit from the application of NSN to urea. [ABSTRACT FROM AUTHOR]

It has been reported that nitrogen (N) deficiency can significantly reduce grain iron (Fe) and zinc (Zn) concentrations in wheat. Here, we investigated the grain Fe (GFeC) and Zn (GZnC) concentrations of 42 Chinese wheat varieties grown in a field trial under low and high N conditions. Analysis of variance revealed that both GFeC and GZnC significantly differed among varieties and between N treatments, and significant interactions existed between variety and N treatment. The GFeC under the low N condition was 94.8% of that under high N condition, ranging from 79.4% to 112.7%; the GZnC under low N condition was 74.8% of that under high N condition, ranging from 59.5% to 102.5%. Wheat varieties with high GFeC and GZnC under both N conditions were identified, and this kind of varieties is desirable in breeding wheat with enriched Zn and Fe under a range of soil N conditions. [ABSTRACT FROM AUTHOR]

A field experiment was conducted for two cropping cycles to evaluate the growth and yield responses of four plantain genotypes (29525, 30456-3, PITA 14 and Agbagba) to fertilizer source (inorganic, organic fertilizer and no fertilizer) in a 4 × 3 factorial in a complete randomized block design. Genotype 29525 flowered and matured earliest, produced heaviest bunches and highest number of hands and fruits per bunch. Agbagba produced the tallest plants, longest, widest and heaviest fruits. Bunch weight was heavier with the application of inorganic or organic fertilizers. There were genotype and fertilizer interactions for bunch and fruit weights and length in the plant crop with genotype 29525 having the heaviest bunches whereas the heaviest and longest fruits were produced by Agbagba when no fertilizer was applied. Bunch yield per hectare increased with organic fertilizer application. [ABSTRACT FROM AUTHOR]

A pot culture experiment of nitrogen forms [nitrate (NO-3): ammonium (NH+4)] with four ratios (100:0, 75:25, 50:50, and 25:75) in nutrient solutions was conducted to examine the effect of nitrogen forms on the growth and polyamine contents of developing seeds of vegetable soybean [Glycine max (L.) Merr. cv. 'Li-xiang 95-1']. Results showed that the best plant growth vigor was observed in [image omitted] (75%), and then in [image omitted] (50%). However, the fresh and dry weight of biomass decreased when a high concentration of either [image omitted] (100%) or [image omitted] (75%) was the primary nitrogen source in the nutrient solution. The numbers of flowers and pods in [image omitted] (75%) were significantly decreased compared with other ammonium-nitrate ratios in which the numbers of flowers and pods were not influenced by nitrogen forms. During the development of seeds, levels of free Put and Spd decreased, and the decrease extents were more marked in 100:0 and 25:75 ([image omitted]:[image omitted]), but the change of free Spm was opposite. Levels of conjugated and bound polyamines in all nitrogen forms increased, but the increases in 75:25 and 50:50 ([image omitted]:[image omitted]) were not so obvious as in 100:0 and 25:75 ([image omitted]:[image omitted]) treatments. The possible roles of polyamines in the adaptive mechanism of vegetable soybean seeds to different nitrogen forms were discussed. [ABSTRACT FROM AUTHOR]

A two-year field experiment was carried out in a typical Mediterranean environment (Foggia, Southern Italy) to evaluate the effect of the reduction of nitrogen (N) fertilization on yield, quality, N uptake, N utilization efficiency, and on environmental impact of processing spinach (Spinacia oleracea L.). In a completely randomized experimental design with four replications, 50, 75, and 100% (150, 225, and 300 kg N ha-1, respectively) of the normal rate applied by the farmers in the trial area were compared. In both years, the total amount of the urea fertilizer applied was broadcasted three times. The results obtained indicate that a lower N fertilization level ensured a satisfactory yield, increased quality and N utilization efficiency. However, crop performances and the amount of N available for leaching were dependent by the weather conditions occurred during plants growth, being significant the year × N fertilization rate interaction. [ABSTRACT FROM AUTHOR]

Best nitrogen (N) management practices are most important for increasing maize (Zea mays L.) productivity and profitability in Northwest Pakistan. Field experiments were performed at the New Developmental Research Farm of NWFP Agricultural University, Peshawar during summer 2002 and 2003. Factorial experimental treatments were two plant densities (D1 = 60,000 and D2 = 100,000 plants ha-1) and three N rates (N1 = 60, N2 = 120 and N3 = 180 kg N ha-1) as main plots, and six split N applications in different proportions at different growth stages of maize (cv. 'Azam') in two equal, three equal, three unequal, four equal, five equal and five unequal splits at sowing and with first, second, third, and fourth irrigation at two week intervals as subplots. Application of the higher N rate (180 kg ha-1) with 4 to 5 splits significantly increased leaf, stem, ear, and total plant dry weight at silking and physiological maturity as well as grain yield plant-1 at both low and high plant densities. Variation in dry matter partitioning and grain yield in maize due to fluctuation in the rainfall data of the two years suggests zonal specific effective N management practices for sustainable maize production in different agro-ecological zones of Northwest Pakistan. [ABSTRACT FROM AUTHOR]

Various manganese fertilizers [manganese sulfate (MnSO4·3H2O (MS), 27% manganese (Mn); and Mn-ethylenediaminetetraacetic acid (EDTA) (ME), 12% Mn] and their doses (0, 6, 9, 12 mg Mn kg-1 and 0, 0.2, 0.3, 0.4%) were applied to soil and sprayed on leaves to study the variations in yield and yield components (plant height, number of pod per plant, number of grain per pod, thousand grains weight, and protein) of dwarf bean (Phaseolus vulgaris L. cv. 'Akman-98') grown under Konya (Turkey) ecological conditions during two consecutive growing seasons in 2006 and 2007. Field experiments were conducted in randomized block split plot design with four replications. All soil applications were made on bands as a single application at sowing whereas foliar applications were made in two sprays on the 25th and 35th days after seed emergence. According to the results, foliar application of ME resulted in better yield and yield components than the MS application and all types of soil applications. The highest grain yields were obtained by the 0.2% of ME sprayed on the leaves in the first year (2783.4 kg ha-1) and that of 0.3% of ME also sprayed onto the leaves in the second year (3092.1 kg ha-1). [ABSTRACT FROM AUTHOR]

Wheat cultivars ('AC Barrie', 'Brook Field', 'Hoffman', and 'Norwell') with different protein concentrations were compared under four nitrogen (N) levels (0, 50, 100 and 150 kg ha-1) in an environment-controlled greenhouse, and the same experiment with an additional N level (200 kg N ha-1) was repeated in the field in 2007. In the greenhouse experiment, application of 100 kg N ha-1 resulted in significantly greater grain yield due mainly to higher number of grains per spike and heavier mean grain weight; in the field study, the 150 kg N ha-1 treatment produced the greatest yield (P<0.01) primarily due to more number of grains per spike. Crude grain protein percentage was increased significantly with each increment of N up to the highest level; however, protein yield (kg ha-1) increased significantly with fertilizer up to 150 kg N ha-1. Leaf chlorophyll contents were increased linearly with increment of N levels up to 150 kg ha-1 both in the greenhouse and field trials while leaf area indices continued to increase up to the highest application rate (200 kg N ha-1). Canopy reflectance, expressed as normalized difference vegetation index (NDVI), attained maximum value with 150 kg N ha-1 in the field experiment. Among the varieties tested, “Hoffman” out-yielded other three varieties due to heavier grain weight. Although highest grain and/or plant crude protein content were recorded in 'AC Barrie', it was the variety 'Hoffman' that produced the highest total protein (kg ha-1) with largest NDVI and leaf area index (LAI) values. [ABSTRACT FROM AUTHOR]

High concentrations of bicarbonate (HCO-3) cause alkalinity of irrigation water and are associated with suppression in plant growth and micronutrient deficiencies, such as iron (Fe) and zinc (Zn). Because reports indicate that the deleterious effects of alkalinity may be counteracted partially by supplementary potassium (K+) or ammonium (NH4+) an experiment was designed to evaluate the response of bean plants (Phaseolus vulgaris L.) grown in high alkalinity conditions to varying proportions of NH4+, K+, or sodium (Na+) (as a potential substitute for K+). Plants established in a growth chamber were grown in hydroponics for 21 days in solutions containing 5 mM HCO-3 and a total of 5 mM of a mixture of NH4+, K+, and Na+. The proportions of NH4+, K+, and Na+ were designed according to mixture experiment methodology. Total N in all the mixture treatments was maintained at 10 mM by using nitrate (NO-3)-N, thus the NH4+:NO-3 ratio varied according to the proportion of NH4+ in the mixtures. Alkalinity caused suppression in plant growth and chlorophyll concentration in the younger leaves, whereas excessive NH4+ was associated with leaf scorching and decreased leaf expansion. High proportions of K+ alleviated alkalinity symptoms and produced higher shoot and root dry mass provided that NH4+ was included in the mixture. However, a proportion of NH4+ higher than 0.333 in the mixture (>1.66 mM NH4+) induced toxicity. The highest shoot dry mass occurred if the NH4+:NO-3 ratio was 0.19:0.81 and the NH4+:K+:Na+ proportion was 0.38:0.38:0.24 (1.9 mM NH4+ + 1.9 mM K+ + 1.2 mM Na+). Thus, an improvement in plant growth is achieved when NH4+, K+, and Na+ are blended together, in spite of the high alkalinity treatment imposed. Optimum NH4+ was associated with a decrease in solution pH and an increase in shoot Fe and Zn concentration. [ABSTRACT FROM AUTHOR]

Field experiments were conducted at Cereal Crops Research Institute Pirsabak Nowshera, Pakistan, for two years (2003-2004 and 2004-2005) to evaluate the effects of nitrogen (N) and sulfur (S) levels and their methods of application on quality parameters of canola (Brassica napus L. cv. 'Bulbul-98'). Four levels of S (0, 20, 40, and 60 kg ha-1) and three levels of N (80, 120, and 160 kg ha-1) and a control treatment (with both nutrients at zero level) were applied as a sole dose at sowing, in two split applications (half each at sowing and leaf rosette stages) and three split applications (one third each at sowing, leaf rosette stage, and early flowering). Large increases in oil and protein concentrations were measured at 40 kg S ha-1 while no further significant increase was observed at 60 kg S ha-1. However, increasing level of S consistently increased glucosinolate concentrations to the highest level of 60 kg S ha-1. Nitrogen significantly increased protein concentrations up to the maximum level of 160 kg N ha-1 while glucosinolate concentrations were increased up to 120 kg N ha-1. However, oil concentrations showed negative trend to increasing level of N. [ABSTRACT FROM AUTHOR]