Efficiency of Sulfur Application on Soybean in Two Types of Oxisols in Southern Brazil

Modern agricultural techniques have been increasing the yield of soybean (Glycine max (L.) Merr.) while also causing increasing removal of sulfur (S) from the soil. Besides this, the use of concentrated fertilizers with this element and inadequate soil management, with consequent formation of organic matter with low S concentrations, has been causing frequent symptoms of deficiency in the plants. To assess the effect of S on soybean yield and to establish critical levels of sulfur sulfate (S-SO₄^2-) available in the soil, two experiments were conducted over a 2-year period in the Paraná State, Brazil, in fields containing Typic Haplorthox and Typic Eutrorthox soils, located in the Ponta Grossa and Londrina Counties, respectively. The experimental design was randomized blocks with five S rates (0, 25, 50, 75, and 100 kg ha^?1) and four replicates. The source used was elementary S with 98 percent purity. The maximum estimated yields on average for the 2 years were obtained with application of 49.9 and 63.0 kg ha^?1 in the Typic Haplorthox and Typic Eutrorthox soils, for an overall average of 56.4 kg ha^?1, with concentrations of available S-SO₄^2- in the 0- to 20-cm depth of 16.9, 19.3m and 17.1 mg kg^?1, respectively, values greater than the 10 mg kg^?1 indicated as the adequate concentration for soybean plant. In turn, at the 21- to 40-cm depth, the S concentrations were 49.5, 74.2, and 56.4 kg ha^?1. The efficiency of the fertilization diminished with increasing S rates, in both soil types, while the greatest yield efficiency was obtained in the plants grown in the Typic Haplorthox soil.     

Lime and Cattle Manure in Soil Fertility and Soybean Grain Yield Cultivated in Tropical Soil

Most tropical soils have high acidity and low natural fertility. The appropriate application of lime and cattle manure corrects acidity, improves physical and biological properties, increases soil fertility, and reduces the use of chemical and/or synthetic fertilizers by crops, such as soybean, the main agricultural export product of Brazil. This study aimed to assess the effects of the combination of the application of dolomite limestone (0, 5, and 10 Mg ha^?1) and cattle manure (0, 40, and 80 Mg ha^?1) on grain yield and the chemical properties of an Oxisol (Red Latosol) cultivated with soybean for two consecutive years. The maximum grain yield was obtained with the application of 10 Mg ha^?1 of lime and 80 Mg ha^?1 of cattle manure. Liming significantly increased pH index, the concentrations of calcium (Ca²⁺) and exchangeable magnesium (Mg²⁺), and cation exchange capacity (CEC) of soil and reduced potential acidity (H⁺ + Al³⁺), while the application of cattle manure increased pH level; the concentrations of potassium (K⁺), Ca²⁺, and exchangeable Mg²⁺; and CEC of the soil. During the 2 years of assessment, the greatest grain yields were obtained with saturation of K⁺, Ca²⁺, and Mg²⁺ in CEC at the 4.4, 40.4, and 17.5 levels, respectively. The results indicated that the ratios of soil exchangeable Ca/Mg, Ca/K, K/Mg, and K/(Ca+Mg) can be modified to increase the yield of soybean grains.     

Response of Soybean to Phosphorus Fertilization in Brazilian Oxisol

Soybean is an important grain crop for Brazil, and phosphorus (P) plays an important role in improving yield of this crop in Brazilian Oxisols. Data are limited on influence of P sources and rate on soybean yield, yield components, and P-use efficiency. A field experiment was conducted for 3 consecutive years to determine response of soybean to three fertilizers (single superphosphate, Yoorin, and Arad) with 0, 17.5, 35, and 52.5 kg P ha^?1 (0, 40, 80 and 120 kg P₂O₅ ha^?1). Grain yield was significantly influenced by phosphorus fertilization. Overall, maximum grain yield was produced by application of single superphosphate, followed by Yoorin and Arad. Number of grains per pod and 100-grain weights were also influenced significantly by P fertilization. Shoot dry weight, number of pods per plant, and grain harvest index had a significant positive association with grain yield. Phosphorus uptake in grain was about six times more than uptake in shoots, and P uptake in grain had a significant positive association with grain yield. Phosphorus-use efficiency (kg grain/kg P applied or uptake) decreased with increasing P rate, and it was greater for single superphosphate than for Yoorin and Arad sources of P fertilization. However, P-utilization efficiency (kg grain plus straw yield / P uptake in grain plus straw) was greater under Yoorin treatment compared to the two other sources of P.     

High P Availability in Brazilian Cerrado Soils Reduces Nodulation and Grain Yield of Soybean

The aim of this work was to evaluate the effect of phosphorus (P) levels on nodulation and soybean production components in Cerrado soils. The experimental design was randomized in blocks, with five replicates, and four consecutive crop seasons (2013/2014, 2014/2015, 2015/2016, and 2016/2017), being cultivated in the same experimental field area. In the first three crop seasons phosphate fertilization were carried out establishing the treatments of increasing levels of P: 0, 43.6, 87.3, 131.0, and 174.6 kg ha^?1, and an additional level (farm standard) of 42 kg ha^?1. The results of this work refer to the crop season 2016/2017 without different P application, evaluating the influence of content of previous crop seasons. The dry weight of roots, plant population, thousand grains weight, grain yield, nitrogen (N) and P content in leaves, number and dry weight of nodules were evaluated in the reproductive stages (R2 and R8) of soybean. Increasing levels of P in soil provided significant effects on nodulation, morphological components and production of soybean plants. Levels above 40 mg dm^?3 of P available in soil provided a reduction in the number and dry weight of the nodules that are highly correlated to reduction on grain yield.     

Sulfur Use Efficiency in Soybean Cultivars Adapted to Tropical and Subtropical Conditions

Sulfur (S) is an essential nutrient in crop plants and one of the components of amino acids (AAs) and proteins. Studies about sulfur efficiency on soybean cultivars [Glycine max (L) Merril] adapted to the tropical and subtropical conditions are still incipient. In Brazil, one experiment under greenhouse conditions evaluated the S-efficiency from eight soybean cultivars. The plants cultivated in a Typic Quartzipsamment received two S rates (0 and 80 mg kg^?1). The grain yield (GY), shoot dry weight (SDW), and the relative yield (RY) had influence from the S rates. The cultivars BRS 295RR and BRS 360RR were the most efficient in using the S application. The number of pods per plant (NPP), photosynthetic rate (A), nitrate reductase (N-NO₂^?), and chlorophyll significantly increased with de 80 mg kg^?1 of S. By contrast, the internal concentration of carbon dioxide (CO₂) (Ci) was reduced. Similarly, there were increases in the concentration of nitrogen (N), phosphorus (P), magnesium (Mg), and N:S ratio in the leaves and grain, but the K increased only in the leaves. Comparing the cultivars, only the N concentration in the leaves and the Mg in the grain had non-significant differences.     

Yield,Yield Components,Soil Chemical Properties,Plant Physiology,and Phosphorus Use Efficiency in Soybean Genotypes

Expansion of soybean [Glycine max (L.) Merrill] cultivated in Brazil to regions with low fertility soils gave rise to studies on the possibility of obtaining highly productive cultivars with high nutrient use efficiency. An experiment in greenhouse conditions was conducted to assess phosphorus (P) use efficiency (PUE) by 13 soybean genotypes. The genotypes were grown in an Ustoxix Quartzipsamment with two P rates [0 (no P application) and 150 mg P kg^?1], whose source was monoammonium phosphate (MAP, P₂O₅ 44%). Shoot dry weight (SDW), grain yield (GY), grain harvest index (GHI), relative yield (RY), and physiological components (photosynthetic rate, stomatal conductance, respiratory rate, and internal CO₂ concentration) were influenced by soybean genotypes and P rates. Genotypes BMX Apolo RR, BRS 360RR, BRS 378RR, CD 219RR, DM 2302RR, TMG 7161RR, and Vtop RR were classified as non-efficient and non-responsive to P application, while BMX Potência RR, Vmax RR, FPS Solar RR, NA 5909RR, TMG 1066RR, and M 6210 IPRO were classified as efficient and responsive. Phosphorus application increased the values of physiological components, which was not observed for N, K, Ca, Mg, and S concentration in the leaves and grains. Soybean genotypes selection for increased P efficiency could help growers overcome the problem of soybean cultivation on new areas or degraded pastures.     

Influence of Lime and Gypsum on Yield and Yield Components of Soybean and Changes in Soil Chemical Properties

Soybean is one of the most important legume crops in the world. Two greenhouse experiments were conducted to determine the influence of liming and gypsum application on yield and yield components of soybean and changes in soil chemical properties of an Oxisol. Lime rates used were 0, 0.71, 1.42, 2.14, 2.85, and 4.28 g kg^?1 soil. Gypsum rates applied were 0, 0.28, 0.57, 1.14, 1.71, and 2.28 g kg^?1 soil. Lime as well as gypsum significantly increased grain yield in a quadratic fashion. Maximum grain yield was achieved with the application of 1.57 g lime per kg soil, whereas the gypsum requirement for maximum grain yield was 1.43 g per kg of soil. Lime significantly improved soil pH, exchangeable soil calcium (Ca) and magnesium (Mg) contents, base saturation, and effective cation exchange capacity (ECEC). However, lime application significantly decreased total acidity [hydrogen (H) + aluminum (Al)], zinc (Zn), and iron (Fe) contents of the soil. The decrease in these soil properties was associated with increase in soil pH. Gypsum application significantly increased exchangeable soil Ca, base saturation, and ECEC. However, gypsum did not change pH and total acidity (H + Al) significantly. Adequate soil acidity indices established for maximum grain yield with the application of lime were pH 5.5, Ca 1.8 cmol_c kg^?1, Mg 0.66 cmol_c kg^?1, base saturation 53%, Ca saturation 35%, and Mg saturation 13%. Soybean plants tolerated acidity (H + Al) up to 2.26 cmol_c kg^?1 soil. In the case of gypsum, maximum grain yield was obtained at exchangeable Ca content of 2.12 cmol_c kg^?1, base saturation of 56%, and Ca saturation of 41%.     

Variability on Yield,Nutritional Status,Soil Fertility,and Potassium-Use Efficiency by Soybean Cultivar in Acidic Soil

The use of cultivar with nutrient-use efficiency is an important strategy in the management of plant nutritional status, particularly potassium (K), because its high demand and the progressive impoverishment caused by the use of inadequate amounts cause frequent deficiency symptoms observed in soybean [Glycine max (L.) Merrill] crops. This study was conducted in greenhouse conditions in a completely randomized design with four replicates in an Typic Quartzipsamment soil aimed to assess the effect of applying two rates of K (50 and 200 mg kg^?1) on growth, shoot dry weight yield (SDWY) and seed yield (SY), nutritional status, yield components, and efficiency of K use in eleven cultivars of different characteristics and growth habits. The SDWY, SY, number of seeds per pod, number of pods, and estimated 100-seed weight showed significant interaction between cultivar and the K rates, with greater values at the rate 200 mg K kg^?1. Similarly, the concentration of nitrogen (N), phosphorus (P), K, calcium (Ca), magnesium (Mg), sulfur (S), boron (B), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn) in leaves and grains varied according to the K rates and in the cultivar. The most K-use efficient cultivars were BMX Magna RR, BRS 232, BRS 284, BRS 294RR, NA 5909RR, and Vmax RR, whereas FTS Campo Mourão RR was inefficient. Regarding response to fertilization, the cultivars Vmax RR, BMX Magna RR, NA 5909RR, BRS 284, and BRS 294RR were found to be efficient and responsive, whereas the cultivar FTS Campo Mourão RR, BRS 232, BMX Potência RR, BRS 295RR, TMG 1066RR, and TMG 1067RR are inefficient and responsive to K application in the soil.     

Interaction of Glyphosate with Zinc for the Yield,Photosynthesis, Soil Fertility and Nutritional Status of Soybean

Application of glyphosate herbicide in genetically modified (GM) soybean [Glycine max (L.) Merrill] in soils with low zinc (Zn) concentration may interfere in the uptake of this and other nutrients, with negative impact on productivity. Thus, an experiment was conducted in greenhouse conditions on Ustoxix Quatzipsamment soil to investigate the effects of the interaction of glyphosate with Zn for the yield, photosynthesis, soil fertility and nutritional status of soybean. The treatments consisted of two soybean varieties [BRS 133 (conventional—NGM) and its essentially derived transgenic line BRS 245RR (GM) with and without glyphosate application] and five Zn rates (0, 5, 10, 20 and 40 mg kg^?1, source zinc sulfate (ZnSO₄)), with four replicates. Except for the copper (Cu) and iron (Fe) concentrations, the introduction of the herbicide-resistant gene is the predominant factor reducing nutrient uptake, photosynthetic (A) rate, stomatal conductance (Gs), leaf chlorophyll and ureide concentrations. The administration of Zn rates lowered the leaf phosphorus (P) concentration, and there was significant increase in Zn concentration in the soil and in the plant. Except for the 20 mg kg^?1 of Zn rate, the use of the herbicide did not affect the shoot dry weight (SDW) and seed yield, and on average, the maximum seed yield was obtained with Zn concentrations of 26.4 and 18.7 mg kg^?1 extracted by Mehlich 1 and diethylenetriaminepentaacetic acid-triethanolamine (DTPA-TEA), respectively.     

Soybean response to copper applied to two soils with different levels of organic matter and clay

Abstract

Increasing the amount of soil organic matter (OM) alters the availability of copper (Cu) for plants under tropical and subtropical conditions. With the aim of evaluating the effects of the OM/Cu interaction on the soybean crop, a trial was conducted with a fully randomized 2?×?5 factorial design and four replicates. The treatments consisted of five Cu rates (0, 1, 2, 4 and 8?mg kg^?1) and two soil types: Typic Oxisol and Typic Ultisol. The soybean responded to fertilization with Cu, producing the highest estimated grain yield at a rate of 4.1?mg kg^?1. Similarly were also observed for shoot dry weight, number of pods and root length. The soil chemical properties and nutrient levels in the leaves and grain were influenced only by the soil type, whereas physiological components were affected in terms of photosynthetic rate and intercellular CO₂ concentration.     

施氮量对新增耕地肥料利用及大豆产量的影响

在晋西黄土区新增耕地设置施加N0,N1,N2,N3,N4和N5六种不同氮水平氮肥的处理,比较分析不同施氮量对氮肥利用率、氮磷钾吸收累积、大豆生长发育和产量的影响,并通过回归拟合,确定最佳施氮量,结果表明:不同氮水平下,氮肥农学利用率、氮肥吸收利用率和氮肥偏生产力随施氮量的增加呈现下降的趋势,而各氮水平条件下氮肥生理利用率差异不大;施氮能够促进大豆植株各部位对氮、磷、钾的吸收利用,各处理之间大豆植株氮素累积量、磷素累积量和钾素累积量差异显著,且在N2水平下最高,但大豆植株氮、磷、钾累积量与施氮量相关性不显著;N2水平下大豆植株在出枝期、开花期和鼓粒期的株高、冠幅均最高,且大豆产量最高,达188.83g/m2,比其他五种处理措施增产8.68%~141.32%,其增产效益最高,为0.562元/m2;晋西黄土区新增耕地的最佳施氮量为168~178kg/hm2,对应理论产量为1 800~1 802kg/hm2。     

Bioavailability of Nutrients in Seeds from Tropical and Subtropical Soybean Varieties

The selection of varieties or species of plants with higher nutrient uptake efficiency and nutrient concentration for biofortification of food crops is a key tool to reduce malnutrition. Soybean (Glycine max L. Merr) is one of the most important food crops, because it is consumed directly or indirectly, in the form of seeds, processed (milk and/or derivatives), or used as a protein component of animal feed worldwide. In order to select plants with higher nutrients concentration in seeds, 24 soybean varieties for tropical and subtropical conditions and different general features were assessed. There was great variability in photosynthesis rate, chlorophyll content, seed yield (SY), and concentration and uptake of nutrients by seeds between the varieties. Not genetically modified (NGM) crops showed higher nitrogen (N), cooper (Cu), and manganese (Mn) concentration and higher N, potassium (K), Cu, iron (Fe), Mn, and zinc (Zn) uptake, while for genetically modified (GM) crops only calcium (Ca) concentrations were higher. Varieties BRS 284 and BMX Magna RR showed the highest nutrients concentrations in the group with the highest nutrient efficiency. The genetic variability observed among the varieties regarding uptake and translocation of nutrients into seeds allows selecting more promising materials to be used in the biofortification of nutrients in soybean seeds.     

Effects of Goat Manure and Lime Addition on Phosphate Sorption by Two Soils from the Transkei Region,South Africa

More than 40% of soils in the Transkei region, South Africa, have high phosphorous (P) fixation capacities that necessitate application of high P fertilizer rates. This incubation study compared the effectiveness of goat manure (GM) and lime to minimize P sorption in two such soils. Manure application reduced P sorption in both soils, which was partly attributed to the liming effect of GM that resulted in marked reductions of exchangeable aluminum (Al). The liming effect of GM rates followed the order 20 t GM ha^?1 > 10 t GM ha^?1 > 5 t GM ha^?1. Therefore, GM can be cost‐effectively used to lime acid soils in the region and reduce their Al toxicity potential and P fertilizer requirements. Liming reduced P sorption on the Chevy Chase soil soon after application, but P sorption was reduced after 2 months on the Flagstaff soil, suggesting that the timing of liming for improved P availability could be critical for some soils.     

Changes in Physical Properties of Soils with Land Use Time in the Brazilian Savanna Environment

Soils from central Brazil have been intensively used over the last decades because of the rapid conversion of savannas ( Cerrado ) into corn/soybean fields. The objective of this work is to study modifications in the physical properties of soils in the Rio Verde watershed, as a function of the land use time for agriculture, determined from classification of Landsat satellite images between 1980 and 2010. Soil samples were collected at surface (0–20 cm) and subsurface (20–40 cm) horizons for the different classes of land use time (<10, 10–20, 20–30, and >30 years). The following physical properties were measured: bulk density (BD), air permeability (K_a), penetration resistance (PR), microporosity (MI), macroporosity (MA), and total porosity (TP). Results showed a strong expansion with time of agriculture that occupied 35·3% (1980), 37·4% (1990), 51·3% (2000), and 60·9% (2010) of the watershed area. When properties were compared with those from the reference areas (preserved soils under native vegetation), significant differences were observed for all the physical attributes of soils for a land use time higher than 20 years. Overall, BD and PR increased with land use time, and the opposite was verified for K_a, MA, and TP. Some physical properties presented values (e.g., 1·54 g cm⁻³ for BD and 0.06 cm³ cm⁻³ for MA) close to the critical ones reported to affect crop development, but they were not still impacting on local soybean yield. Copyright © 2013 John Wiley & Sons, Ltd.     

Genotypic Variation in Shoot Cadmium Concentration in Rice and Soybean in Soils with Different Levels of Cadmium Contamination

A pot experiment was conducted to investigate whether the shoot cadmium (Cd) concentration in 11 rice and 10 soybean cultivars varied among 4 soils with different levels of Cd contamination. Significant differences in shoot Cd concentration were found among rice or soybean cultivars grown in the 4 soils. The ranking of the rice cultivars for the shoot Cd concentration varied considerably among the soils. On the other hand, the soybean cultivars were ranked similarly in terms of shoot Cd concentration in the 4 soils. Significant and positive correlations were found between the Cd and Zn concentrations and between the Cd and Mn concentrations in the shoot of rice cultivars, when they were grown in 2 soils with relatively moderate levels of Cd contamination. The shoot Cd concentration in the soybean cultivars, however, was not correlated with the concentrations determined for any of the metals (Zn, Mn, Cu, and Fe) across the 4 soils. Significant and positive correlations between the concentrations of Cd in younger shoots and mature seeds were detected among the soybean cultivars in 2 soils used, unlike among the rice cultivars, indicating that it may be difficult to evaluate the genotypic variation in seed Cd concentration using relatively younger shoots in the case of rice. These results revealed that genotypic differences in shoot Cd concentration in rice or soybean are variable or invariable among soils, respectively.     

Influence of Long-term Tillage,Straw, and N Fertilizer Management on Crop Yield,N Uptake,and N Balance Sheet in Two Contrasting Soil Types

Field experiments (established in autumn 1979, with monoculture barley from 1980 to 1990 and barley/wheat–canola–triticale–pea rotation from 1991 to 2008) were conducted on two contrasting soil types (Gray Luvisol [Typic Haplocryalf] loam soil at Breton; Black Chernozem [Albic Agricryoll] silty clay loam soil at Ellerslie) in north-central Alberta, Canada, to determine the influence of tillage (zero tillage and conventional tillage), straw management (straw removed [S_Rem] and straw retained [S_Ret]), and N fertilizer rate (0, 50 and 100 kg N ha^?1in S_Ret, and only 0 kg N ha^?1in S_Rem plots) on seed yield, straw yield, total N uptake in seed + straw (1991–2008), and N balance sheet (1980–2008). The N fertilizer urea was midrow-banded under both tillage systems in the 1991 to 2008 period. There was a considerable increase in seed yield, straw yield, and total N uptake in seed + straw with increasing N rate up to 100 kg N ha^?1 under both tillage systems. On the average, conventional tillage produced greater seed yield (by 279 kg ha^?1), straw yield (by 252 kg ha^?1), and total N uptake in seed + straw (by 6.0 kg N ha^?1) than zero tillage, but the differences were greater at Breton than Ellerslie. Compared to straw removal treatment, seed yield, straw yield, and total N uptake in seed + straw tended to be greater with straw retained at the zero-N rate used in the study. The amounts of applied N unaccounted for over the 1980 to 2008 period ranged from 1114 to 1846 kg N ha^?1 at Breton and 845 to 1665 kg N ha^?1 at Ellerslie, suggesting a great potential for N loss from the soil-plant system through denitrification, and N immobilization from the soil mineral N pool. In conclusion, crop yield and N uptake were lower under zero tillage than conventional, and long-term retention of straw suggests some gradual improvement in soil productivity.     

沿淮地区氮磷肥配合对水稻产量和肥料利用效率的影响

在沿淮变性土区开展了氮磷配合对水稻产量和肥料利用效率影响的田间试验。结果表明,施氮增产28.9%～62.2%,施磷增产4.3%～4.7%,氮磷配合有利于产量和肥料利用效率的提高。通过数学模拟,获得氮磷肥的效应方程,并计算出最大经济施肥量,氮肥为269.5kg hm-2,磷肥为90.4kg hm-2。     

氮肥配施增效剂实现寒地水稻增产、提质与增效

研究氮肥增效剂对寒地水稻产量、品质及氮素利用的影响,旨在为制定合理的稻田氮素管理措施及增产、提质和增效策略提供科学依据。2017年和2018年在黑龙江省方正县设置田间试验,研究氮肥配施硝化抑制剂和脲酶抑制剂对水稻产量、品质、氮素利用和转化及经济收益的影响。结果表明:尿素配施硝化抑制剂CP和脲酶抑制剂NBPT(N+NI+UI)显著提高水稻产量,2017年较氮肥处理(N)水稻籽粒、秸秆和总生物量分别增产6.4%,4.9%和5.8%,2018年分别增产8.8%,7.2%和8.2%。施用氮肥增效剂可以提高寒地水稻碾磨品质、外观品质和营养品质,并促进水稻氮素吸收,提高氮肥利用效率。与N处理相比,N+NI+UI处理水稻氮肥表观利用率、氮肥农学效率和氮肥偏生产力分别提高15.6%,19.1%和7.6%。CP和NBPT配施对氮素转化表现出明显的协同抑制效果,延迟和降低土壤NH4^+—N含量峰值,保持水稻生育期较高的NH4^+—N含量,延长了氮素供应时间。施用氮肥增效剂可使寒地水稻增收2499.08元/hm^2。可见,寒地水稻氮肥配施硝化抑制剂CP与脲酶抑制剂NBPT能够延长氮素释放周期,促进水稻氮素吸收,增加水稻产量,改善水稻品质,提高氮肥利用效率,增加经济效益。     

秸秆还田和有机肥配合替代1/3化肥对旱地玉-麦产量、蛋白质含量和化肥利用效率影响

为研究长期秸秆还田和有机肥配合替代部分化肥对玉-麦一年两熟种植下产量、品质和化肥效率的影响,2015-2020年,依托中国农业科学院洛阳旱农试验基地始于2007年的长期定位试验,设置不施肥对照(CK)、玉米小麦季均常规施用氮磷钾化肥(NPK)、秸秆还田和有机肥配合替代小麦季1/3氮磷钾化肥(SORF) 3个处理,研究2015—2020年玉-麦一年两熟种植下作物产量、化肥利用效率,2019—2020年玉米和小麦籽粒氮磷钾养分含量、蛋白质含量和蛋白质产量,以及2020年小麦籽粒蛋白质及其组分含量。结果表明:(1)SORF处理玉米增产增效作用优于NPK处理,5年平均产量提高10.0%,但二者间小麦和周年产量差异未达显著水平(p>0.05)。(2)施肥显著提高玉米和小麦籽粒氮磷钾含量,其中SORF较NPK处理又显著增加籽粒氮含量,从而使玉米籽粒蛋白质含量和蛋白质产量较NPK分别显著提高6.7%和17.8%,小麦籽粒蛋白质含量和蛋白质产量分别显著提高8.0%和6.3%,周年蛋白质产量显著增加10.8%。(3)SORF和NPK处理较CK均可显著提高小麦籽粒中各蛋白质组分含量及谷醇比,协同提高小麦籽粒蛋白质含量和籽粒品质。SORF较NPK处理还可提高除球蛋白外的其他蛋白组分含量,但谷醇比的增幅不显著。(4)与NPK相比,SORF处理下玉米、小麦和周年的氮肥农学效率分别显著提高54.8%,31.2%和37.3%,氮肥偏生产力分别显著提高10.0%,45.6%和20.7%,小麦、周年的磷(钾)肥农学效率和偏生产力分别提高31.2%,77.3%和45.6%,55.7%。综合来看,秸秆还田和有机肥配合替代1/3化肥(SORF)不仅有利于提高玉米产量,玉米、小麦的籽粒蛋白质含量和蛋白质产量,以及化肥农学效率和偏生产力,而且可提高小麦籽粒蛋白组分含量,是旱地玉-麦一年两熟区兼顾产量品质效率的施肥模式。     

Mineralization and Nutrient Release of an Organic Fertilizer Made by Flour,Meat, and Crop Residues in Two Vineyard Soils with Different pH Levels

The mineralization and nutrient evolution of an organic fertilizer compost of flour, meat, and crop residues was evaluated in two vineyard soils. A lysimetric testing, using 2.2-L Büchner funnels, was carried out to study the evolution of pH, electrical conductivity, and nutrients during the 400-day experiment. The net mineralization for two different doses of the fertilizer mixed with the soils was compared with an unfertilized control. The pH value of the acidic soil decreased to values less than 4.5 because of the yield of hydrogen (H⁺) in the organic fertilizer mineralization, whereas the soluble aluminium (Al³⁺) increased quickly in the leachates. The mineralization process was quicker in the alkaline soil (with a maximum mineralization rate of 0.83 mg nitrogen (N) kg^?1 day^?1 for the 8 Mg ha^?1 dose and 0.43 mg N kg^?1 day^?1 for the 4 Mg ha^?1 dose) in comparison with the acidic soil, which reduced these rates up to 50%. The N-nitrate (NO₃) amounts yielded in a year were 150 and 79 kg N ha^?1 for the 8 and 4 Mg ha^?1 doses respectively in the alkaline soil, enough to cover the vineyard N demand. These values were reduced to 50% and 60% of N-NO₃ for the acidic soil, indicating the important effect of pH in the mineralization.