Soil boron and soybean leaf boron in relation to soybean yield

Abstract

Boron applied in 2 soybean field experiments at rates up to 2.12 kg/ha was not detectable in Ap or B₂ horizon soil extracts approximately 6 weeks after B addition, although leaf B contents reflected added B. There was a measurable difference between the 2 fields in extractable B. Where the Ap horizon averaged 0.05 ppm B, soybean leaf content ranged 14 to 40 ppm B and no yield response was obtained with 0.56 to 2.24 kg/ha of added B. Where the Ap horizon averaged 0.11 ppm B, and leaf content reached 63 ppm B, soybean yield was reduced approximately two‐thirds by 2.24 kg/ha of added B.

Data from these 2 field experiments and previous micronutrient field studies, where yield response to B fertilization was obtained when leaf B was 9 to 10 ppm in soybean leaves, suggest that plant tissue analyses for B can be used to evaluate B fertilization needs. Soil tests may not be useful for detecting B deficiency in coarse‐textured soils, but may aid in detection of areas where B levels are high.     

Effect of boron and sulfur interaction on some important biological indices in an inceptisol

In most soil ecosystems, soil biological activity and associated processes are concentrated in the rhizosphere soil and is influenced by the external application of plant nutrients. The impacts of boron and sulfur on soil biological properties were evaluated in an Aeric Haplaquept (pH 5.7) growing rapeseed (Brassica campestris L.) as a test crop. Application of boron (B) at 2 mg kg^?1 in combination with sulfur (S) at 30 mg kg^?1 (B₂S₃₀) resulted in highest available Boron and sulfur of 0.239 and 15.4 mg kg^?1, respectively and registered 62.5% and 71.3% increase over control (B₀S₀) at 60 days of crop growth compared to individual applications. The microbial populations viz. phosphate solubilizing microorganisms (PSM) and nitrogen fixing bacteria (NFB) were the highest of 52.63 and 85.87 × 10⁵ g^?1 soil, respectively, CFU in B₂S₃₀ treatment at 60 days and adjudged as the best treatment combination for enhancement of soil biological indices and seed yield.     

Effect of Cattle Manure and Sulfur on Yield and Oil Composition of Pumpkin (Cucurbita pepo var. Styriaca) Inoculated with Thiobacillus thiooxidans in Calcareous Soil

The effect of cattle manure and sulfur fertilizer on seed yield and oil composition of pumpkin (Cucurbita pepo var. Styriaca) under inoculated with Thiobacillus thiooxidans was investigated in a factorial study based on a randomized complete block design. Experimental factors consisted of cattle manure (M) (M₀: 0, M₁: 10; and M₂: 20 t ha^?1), sulfur (S) (S₀: 0, S₁: 250; and S₂: 500 kg ha^?1) and T. thiooxidans (B): inoculated (B₁) and non-inoculated (B₀). Results demonstrated that the application of T. thiooxidans, cattle manure, and S fertilizer decreased the soil pH. The largest number of seed per fruit (367), highest fruit yield (70.57 t ha^?1), seed iron (Fe) content (16.26 mg 100 g^?1), and seed yield (111 kg ha^?1) was obtained when 20 t ha^?1 manure was applied in combination with 500 kg ha^?1 S inoculated with T. thiooxidans. In this condition, the content of S, Fe, phosphorus (P), and nitrogen (N) in plant shoots was increased by 44.8%, 22.58%, 33.89%, and 10.38%, respectively, compared to the control. Moreover, the highest content of seed protein was observed in 10 t ha^?1 manure and 500 kg ha^?1 S fertilizer inoculated with T. thiooxidans. When 250 kg ha^?1 S fertilizer was applied, 20 t ha^?1 manure decreased seed P content sharply. At the rate of 500 kg ha^?1 S fertilizer, the highest content of seed P was obtained from 20 t ha^?1 manure. Totally, 20 t ha^?1 cattle manure, along with 500 kg ha^?1 S fertilizer as well as T. thiooxidans inoculation, improved oil and seed yield of medicinal pumpkin.     

Soil and Rice Responses to Phosphate Fertilizer in Two Contrasting Seasons on Acid Sulfate Soil

Acid sulfate soils (ASS) are characterized by low pH, aluminum (Al), and iron (Fe) toxicity and are typically deficient in phosphate (PO₄). The application of phosphorus (P) fertilizer could help reduce the level of exchangeable Al and Fe, thereby improving the rice growth and yield. Five levels of P (0, 20, 40, 60 and 80 kg phosphorus pentoxide (P₂O₅)/ha) were tested with rice varieties MTL560 in the wet season and MTL480 in the dry season. The optimum rate of P was 60 kg P₂O₅/ha for rice in the dry season and 80 kg P₂O₅/ha in the wet season. Soil testing showed at the start of the season that there was sufficient P in the soil. At the end of the season there was a reduction in soil Al and Fe in plots that had P rates above 40 kg P₂O₅/ha. It is therefore likely that P application reduced Al and Fe toxicity through precipitation and formation of Al-P and Fe-P compounds, which boasted yield, rather amending a soil P deficiency.     

RESPONSE OF SOYBEAN TO SOIL APPLIED SULFUR AND BORON IN A CALCAREOUS SOIL

A greenhouse experiment with soybean grown on sulfur (S) and boron (B) deficient calcareous soil was conducted for two years in northwest India to study the influence of increasing sulfur and boron levels on yield and its attributing characters at different growth stages (55 days, maturity). The treatments included four levels each of soil applied sulfur viz. 0, 6.5, 13.4, 20.1 mg S kg^?1 and boron viz. 0, 0.22, 0.44, 0.88 mg B kg^?1 at the time of sowing. The highest dry matter yield at 55 days after sowing, DAS (19.3 g pot^?1) and maturity (straw yield ?25.2 g pot^?1 and grain yield ?7.3 g pot^?1) was recorded with B_0.44 S_13.4 treatment combination. The combined applications of sulfur and boron yielded highest oil content with B_0.44S_13.4 (21.7%) treatment level. Chlorophyll ‘a’ and ‘b’ increased significantly with successive levels of sulfur and boron addition at 55 DAS. The mean sulfur and boron uptake in straw and grains increased significantly with increasing levels of sulfur and boron up to 13.4 mg kg^?1 and 0.44 mg kg^?1 and decreased non-significantly thereafter. At both the growth stages, a synergistic interactive effect of combined application of sulfur and boron was observed with B_0.44 S_13.4 treatment level for sulfur and boron uptake in straw and grains.     

氮、硫配施对冬小麦氮素利用效率及产量的影响

【目的】氮(N)、硫(S)是生物所必需的营养物质,对小麦籽粒产量和品质起着重要作用。硫素供应不足,特别是在当前大量氮素供应情况下引起的作物生理性缺硫将导致作物产量和含硫氨基酸蛋白质含量下降。本文旨在探索氮、硫配施对冬小麦氮素利用效率和籽粒产量的促进效果并提出合理的区域氮、硫施肥技术。【方法】20122013年,在河南温县以国审冬小麦品种豫麦49-198为供试材料,进行大田试验。设置不同施氮量0、120、180、240和360 kg/hm2(分别以N0、N120、N180、N240和N360表示)和施硫0和60 kg/hm2(S0和S60)试验,调查氮、硫对冬小麦干物质积累、氮素积累分配、籽粒产量和氮素利用效率的影响。【结果】对冬小麦生育后期干物质积累分析表明,干物质积累随施氮量增多而提高,相同施氮量条件下施硫较不施硫小麦干物质积累量显著提高,其中成熟期干物质积累量N180S60、N240S60和N360S60分别较N180S0、N240S0和N360S0提高2225、3607和3120 kg/hm2,而且氮素低的处理添加硫后干物质积累量高于氮素高不加硫处理,如N180S60N240S0、N240S60N360S0,处理间差异均达显著水平。随施氮量增多,冬小麦植株氮素积累总量增加,在N 240和360 kg/hm2水平,硫素供应显著增加小麦植株氮素积累。不同施氮量条件下施硫较不施硫均显著提高了小麦籽粒产量,分别提高了10.5%、18.3%、5.2%、5.6%和4.9%。随施氮量增多,氮肥偏生产力下降,氮回收效率、生理效率和农学效率则均以N 180达最高值。不同施氮水平下,施硫均显著提高了冬小麦氮素回收效率,但对氮生理效率影响不显著,其中在施N量为120、180和240kg/hm2时,施硫较不施硫氮肥偏生产力和农学效率均显著提高。【结论】在当前小麦生产中,采用控氮或减氮增硫技术措施,可实现小麦氮利用效率和籽粒产量的同步提高。在本试验地区小麦生产中,达到冬小麦稳产高效或增产高效的适宜施氮量为180 240 kg/hm2配合60 kg/hm2硫肥施用。     

Optimization of Zinc and Boron Doses for Cauliflower-Maize-Rice Pattern in Floodplain Soil

ABSTRACT

An experiment was replicated simultaneously at two sites of floodplain soils of Bangladesh to find out the optimum application rate of zinc and boron fertilizers for crops under cauliflower-maize-transplant aus rice pattern. Randomized complete block design with three replications was used in the experimentation. The first crop of the pattern received four zinc levels (0, 2.0, 4.0, and 6.0 kg ha^?1), and three boron levels (0, 1.5, and 3.0 kg ha^?1). In second crop, two additional treatments receiving 2.0 kg Zn ha^?1 and 2.0 kg Zn ha^?1 + 1.5 B ha^?1 were added; in the third crop, another four treatments were added by further application of 2 kg Zn ha^?1 in each. Other nutrients viz. N, P, K, and S were used equally at recommended rates for all plots. In such a 3-crop pattern, application of 4.0 kg Zn ha^?1 and 1.5 kg B ha^?1 at a time to the first crop or 2.0 kg Zn ha^?1 to each of the first two crops along with 1.5 kg B ha^?1 to the first crop was sufficient to achieve satisfactory yield of the crops. Considering system productivity, nutrient uptake, and protein and Zn concentrations of crops, the aforesaid doses were found promising.     

Irrigation and nutritional effect on growth and seed yield of coriander (Coriandrum sativum L.)

Optimum quantity of fertilizers and irrigation water to minimize the cost and increase the production is need of the day. Consequently, an experiment was conducted at CCS Haryana Agricultural University, Hisar during the winter season of 2014–15 and 2015–16 to study the effect of irrigation schedules and fertilizer levels on coriander. Irrigation at 25, 50, 75, and 100 days after sowing (DAS) gave higher growth and yield attributing characters, seed yield (16.48 q/ha), biological yield (50.79 q/ha), net return (Rs. 138,950.6), and benefit to cost ratio (2.36), which resulted in 40.9% and 15.3% increase in seed and biological yield over two irrigations, respectively. The application of fertilizers, i.e., N₆₀ and P₅₀ kg/ha, registered higher growth, seed yield attributes, consumptive use of water, whereas, net return and benefit to cost ratio was recorded maximum under fertilizers, i.e., N₇₅ and P_62.5 kg/ha. The interaction effect of irrigation and fertilizer on seeds per umbellet and seed yield was also found to be significantly positive. Hence, in Northern Plains of India four irrigations at 25, 50, 75, and 100 DAS in association with nitrogen 75 kg/ha and phosphorus 62.5 kg/ha is more profitable in coriander crop.     

Response of Sunflower to Sulfur Rate and Time of Application under Two Tillage Systems in a Silty Clay Soil of Dera Ismail Khan Pakistan

ABSTRACT

Sulfur (S) availability is a characteristic of conservation tillage. We studied the effects of S on sunflower yield and fatty acid profile under conventional and conservation tillage in silty clay soil of D.I. Khan, Pakistan. Conventional tillage consisted of disk plowing followed by tiller and rotavator, while conservation tillage comprises tiller and disc harrowing. Treatments comprise six sulfur levels (S₁ = 0, S₂ = 20 kg S ha^?1 at sowing, S₃ = 10 kg S ha^?1 at sowing +10 kg S ha^?1 25 days after sowing (DAS), S₄ = 40 kg S ha^?1 at sowing, S₅ = 20 kg S ha^?1 at sowing + 20 kg S ha^?1 25 DAS, and S₆ = 20 kg S ha^?1 at sowing + 10 kg S ha^?1 25 DAS + 10 kg S ha^?1 50 DAS) replicated thrice. After 2 years of experimentation, soil samples were collected (from 0 to 0.30 m depth) for organic matter (OM), total soil N (TSN), and available sulfur analysis. Conservation tillage significantly increased OM, TSN, and S contents in 0–0.30 m soil compared to conventional tillage. Likewise, sunflower plants showed higher achene yield, better fatty acid profile, and net economic returns in conservation tillage than in conventional tillage. Application of 20 kg S ha^?1 at sowing and 10 kg S ha^?1 at each 25 and 50 DAS recorded significantly higher achene yield, higher oil, and linoleic acid contents; however, oleic and oleic/linoleic ratio did not increase with higher S rates. Conservation tillage was effective in increasing OM, TSN, and available S besides increasing yield and economics in silty clay soil.     

Response of Sunflower to Sources and Levels of Sulfur under Rainfed Semi‐arid Tropical Conditions

Sulfur (S) is one of the severely limited nutrients in rainfed semi‐arid tropical Alfisols. Its application plays an important role in improving the yield and quality of oilseed crops. To identify the optimum level of sulfur for greater yield and oil content in the sunflower crop (MSFH‐8) through suitable sources, a field experiment involving varying levels of S through two sources (gypsum and elemental S) in combination with standard levels of nitrogen (N) and phosphorus (P) was conducted on a sandy loam soil (Typic Haplustalf) at Hayathnagar Research Farm of Central Research Institute for Dryland Agriculture, Hyderabad, situated at an altitude of 515 m above mean sea level and on 78° 36′ E longitude and 17° 18′ N latitude. The response to S application in sunflower crop in terms of growth parameters, yield components, nutrient uptake, and seed oil content was conspicuous. The application of graded levels of sulfur at rates of 20, 40, and 60 kg ha^?1 applied through elemental S significantly increased the seed yield of the sunflower crop over the control by 5.4, 10.7, and 18.1% respectively, whereas the corresponding increases in case of gypsum (CaSO₄·2H₂O) were 25.1, 28.8, and 33.9% respectively. The greatest seed yield of sunflower (1175 kg ha^?1) and percentage oil content (39.7%) was obtained with 60 kg S ha^?1 through gypsum under rainfed conditions. Our study clearly indicated that the application of S at relatively high levels significantly increased the uptake of N, P, and S. The percentage oil content in seed recorded a positive and highly significant relationship with the uptake of N (r = 0.958**), P (r = 0.967**), and S (r = 0.951**), signifying the importance of balanced nutrition in influencing the oil content of seed in sunflower. The application of S through gypsum at rate of 60 kg S ha^?1 along with 40 kg N and 30 kg P₂O₅ ha^?1 was most superior in enhancing the seed yield and percentage oil content in seed.     

Nitrogen,Phosphorus, and Potassium Fertilization of a Coastal Plain Cotton–Peanut Rotation

Abstract

A cotton (Gossypium hirsutum)–peanut (Arachis hypogaea L.) rotation is widely practiced in the southern coastal plain following the reemergence of cotton as a major crop in the 1990s. Very few plant nutrition studies have been conducted in the coastal plain (CP) with modern cotton varieties and none with the cotton–peanut rotation. Experiments with varying rates of nitrogen (N), phosphorus (P), and potassium (K) were conducted to determine if the recommendations from soil tests provide adequate nutrition for maximizing profit when yield goals are Georgia state averages, due to other conditions. From 1996 through 1998, N, P, and K experiments were conducted in cotton crops, and P and K experiments were conducted in peanut crops on Tifton loamy sand. Initial Mehlich‐1 P was 2 to 3 mg/kg (“low”) and Mehlich‐1 K was 50 to 64 mg/kg (“medium” for cotton and “high” for peanut). Each crop was grown each year. State average yields of cotton and peanuts were produced. There was no response in cotton yield to N rates from 34 to 136 kg N/ha. Lack of response may have been due to the fact that the field had not been in production for several years prior to 1996 and there was ample soil mineral N. In 1997 and 1998, residual N provided by N fixation by the previous peanut crop appeared to be sufficient. Maximum profit from P fertilization in cotton was attained at 50 kg P/ha, the recommendation from the soil test. However, a University of Georgia Cooperative Extension Service recommendation to double the P rate for new land with a “low” Mehlich‐1 P soil test was not validated. Cotton yield did not respond to K fertilization even though an application of 55 kg K/ha/year was recommended from the soil test. Peanut yield and grade did not respond to either P or K fertilization. The recommendation from the soil test was 40 kg P/ha/year and no K. Estimates of P removal were 11 kg/ha for cotton and 8 mg/ha for peanut crops. Estimates of K removal were 25 kg/ha for cotton and 22 kg/ha for peanut crops. Over 3 years, soil P was not depleted, but soil K was depleted. Approximately 12 kg P/ha were required to raise soil test P 1 mg/kg and 18 kg K/ha were required to raise soil test K 1 mg/kg (49 lb. P₂O₅ to increase the P test 1 lb./acre, 38 lb. K₂O to raise the K test 1 lb./acre). Additional studies are needed, but the current studies suggest that revisions in recommendations are needed for both cotton and peanut crops.     

土壤高残留氮条件下施氮对夏玉米氮素平衡、利用及产量的影响

土壤残留氮是不容忽视的土壤氮素资源.通过田间小区试验研究了土壤高残留氮下不同施氮量(0、80、160、240和320 kg/hm2)对夏玉米土壤硝态氮积累、氮素平衡、氮素利用及产量的影响,分析了夏玉米的经济效益.结果表明,土壤剖面硝态氮积累量随施氮量的增加而增加,且施氮处理硝态氮积累量显著高于不施氮处理;各施氮处理土壤硝态氮在0-60 cm土层含量最高,在0--180 cm剖面呈先减少后增加的变化趋势.不施氮处理夏玉米收获后土壤无机氮残留量高达378 kg/hm2,随施氮量的增加,无机氮残留和氮表观损失显著增加.作物吸氮量、氮表观损失量与总氮输入量呈显著正相关,总氮输入量每增加l kg作物吸氮量增加0.156 kg,而表观损失量增加0.369 kg,是作物吸氮量的2.4倍.高残留氮土壤应严格控制氮肥用量,以免造成氮素资源的大量浪费.夏玉米籽粒吸氮量随施氮量的增加呈增加的趋势,氮收获指数呈降低的趋势.氮肥农学效率、氮肥生理利用率、氮肥利用率和氮素利用率在施氮量80 kg/hm2时最高,随施氮量的增加降低;增施氮肥能降低高残留氮土壤中氮肥的增产效果和利用率.综合考虑产量、氮素利用和环境效应,N 80 kg/hm2是氮素高残留土壤上玉米的合理施氮量.     

Productivity,profitability and sustainability of rain-fed chickpea under inorganic and biofertilization in foothills of north-west Himalayas

A 4-year (2008–2009 to 2011–2012) study was conducted on the effect of mineral phosphorus (P) + sulphur (S) and biofertilizers on rain-fed chickpea (Cicer arietinum L.) at the Punjab Agricultural University’s Research Station, Ballowal Saunkhri, India. The experiment comprised of five combinations of P and S, viz. control (P₀S₀), no P + 10 kg S ha^?1 (P₀S₁₀), 15 kg P + 10 kg S ha^?1 (P₁₅S₁₀), no P + 20 kg S ha^?1 (P₀S₂₀) and 30 kg P + 20 kg S ha^?1 (P₃₀S₂₀); and three seed inoculation levels, viz. control, Rhizobium and phosphate-solubilizing bacteria (PSB), were laid out in randomized complete block design. Combined application of P + S resulted in improved growth, nodulation, yield attributes and yield. The increase in seed yield over control due to P + S ranged from 11.8% to 17.7%. Seed inoculation with Rhizobium recorded the highest growth, nodulation, yield attributes and yield of chickpea and was statistically at par with PSB and significantly better than no inoculation. Highest benefit/cost ratio (B:C, 2.19) was obtained in P₃₀S₂₀. In view of environmental pollution and high costs of chemical fertilizers, biofertilizers alone or in combination may help to achieve sustainable and ecological agricultural production.     

Fertilization and mineral nutrition of soybean in mesa de Guanipa,Anzoategui State,Venezuela

Abstract

An experiment was conducted on some soils of Mesa de Guanipa, which are sandy, acid (pH 5.5), and have low levels of available P, K, Ca, and Mg. These soils are located at the Agropecuaria Guanipa farm in El Tigre, Anzoategui State, Venezuela. The main objective was to evaluate rates and sources of P, and rates of K on soybean yield (variety FP‐3), which is an activity of the project “Maximum soybean yields in Venezuela”;, financed by the Potash and Phosphate Institute of Canada. The rates and sources of P were 0, 75, and 150 kg P₂O₅/ha as triple superphosphate (TSP) and diammonium phosphate (DAP). Rates of potassium as K₂O were 0, 60, and 120 kg/ha as potassium chloride (KCl). The experimental design was a randomized complete block with 3 replications and a final plant density equivalent to 400,000 plants/ha. A basic application of nitrogen and magnesium fertilizers was made to guarantee the supply of those nutrients. The soybean seeds were inoculated at planting with NITROBAC to ensure nodule formation. Yield results showed a good response to P application and low response to K. The combination of 150 kg P₂O₅/ha as TSP and 60 kg K₂O/ha as KCl produced the maximum soybean grain yields of 2.857 kg/ha at 12% moisture as well as the highest net return of U.S.$393.9/ha. From the results obtained in this experiment as well as ones to be established during the next 3 years, it is expected that there will be an adjustment in the fertilization program followed by the soybean farmers of Mesa de Guanipa as they are now applying higher rates of K and lower rates of P than that applied in this experiment.     

Maize Yield Response to Zinc Sources and Effectiveness of Diagnostic Indicators

Maize yield is often limited by zinc (Zn) deficiency. The objectives of this study were to (i) evaluate maize yield response to Zn applied at four different rates, (ii) evaluate the yield response and agronomic efficiency of maize to the application of a complex fertilizer, MicroEssentials SZ (12N–40P–0K–10S–1Zn), compared to different rates of monoammonium phosphate (MAP) + ammonium sulfate (AS) + zinc sulfate (ZnSO4), and (iii) evaluate the association between tissue Zn concentration and soil-test Zn with the maize response to Zn fertilizer. Eleven experiments were carried out during the 2010, 2011, and 2012 growing seasons throughout eight states in the USA. Treatments consisted of four Zn rates of a physical blend of MAP + AS + ZnSO₄ (0, 2.24, 4.48, 6.72, and 11.2 kg/ha Zn) and MicroEssentials SZ at a Zn rate of 2.24 kg/ha Zn. Nitrogen, phosphorus (P), and sulfur (S) rates were balanced across treatments (40 kg/ha P, 22 kg/ha S) and fertilizers were broadcast and incorporated immediately prior to planting. Treatment and location main effects were significant (P < 0.001) on corn yields, whereas the interaction treatment × location was not (P = 0.33). Maize responded positively to Zn fertilization; average yields across locations increased from 10,540 kg ha^?1 without Zn to 11,530 kg ha^?1 with 11.21 kg Zn ha^?1 applied as a physical blend. The yield response and Zn agronomic efficiency of maize with the application of the complex fertilizer at a rate of 2.24 kg Zn ha^?1 averaged 1004 kg ha^?1 and 448 kg maize kg Zn^?1, respectively, significantly higher (P < 0.1) than the yield response and Zn agronomic efficiency with the application of a physical blend with the same Zn rate, which averaged 293 kg ha^?1 and 131 kg maize kg Zn^?1, respectively. The Zn concentration in plant tissue of unfertilized plots varied greatly and was not related to the maize response to Zn fertilizer (r = 0.01; P = 0.98). With respect to soil Zn, a negative but nonsignificant relationship was found between maize response to Zn fertilizer and soil-test Zn (r = ?0.51; P = 0.16).     

东北黑土区大豆生长、结瘤及产量对氮、磷的响应

氮肥和磷肥显著影响大豆的结瘤和产量。然而在土壤肥力较高、速效养分有效性差的东北地区,有关氮肥和磷肥施用量对大豆结瘤和产量影响的研究较少。本试验采用裂区田间试验,设置3个氮（N）水平（0、20 和 50 kg/hm2）和 3 个磷（P）水平（0、 20 和 40 kg/hm2）,研究氮、 磷及其交互作用对大豆生长发育、 结瘤特征及产量的影响。结果表明, 单施氮肥大豆生物量和产量随着施氮量的增加而增加,而根瘤数量、 干重、 大小和结瘤指数呈逐渐下降的趋势。单施磷肥促进大豆生物量、 产量、 根瘤数量、 干重、 大小和结瘤指数的增加,但其增幅低于施氮处理下的增幅。氮磷对大豆生长和产量促进作用高于单施氮和单施磷处理,但差异不显著;氮磷处理下的根瘤数量、 干重、 大小和结瘤指数低于单施磷处理;氮磷处理下N2（N 50 kg/hm2）处理下的大豆根瘤数量、 干重、 大小和结瘤指数高于N1处理（N 20 kg/hm2）下的,随着施磷量的增加大豆根瘤数量、 干重、 大小和结瘤指数增加,施磷能够抵消氮对大豆根瘤产生和形成的抑制。氮、 磷及其交互作用对大豆根瘤的影响都是直接的,并且不是通过促进大豆生长间接促进的。因此氮和磷均是限制东北地区大豆结瘤和产量的因素,但氮是主导因素。若要获得大豆高产,氮肥施用量需要控制在50 kg/hm2,磷肥在40 kg/hm2;但若想最大的发挥大豆的结瘤固氮功能,那么应该不施或者减少氮肥的施用量到20 kg/hm2,磷肥仍在40 kg/hm2。     

Effect of Organic Manure and Crop Residue Based Long-Term Nutrient Management Systems on Soil Quality Changes under Sole Finger Millet (Eleusine coracana (L.) Gaertn.) and Groundnut (Arachis hypogaea L.) – Finger Millet Rotation in Rainfed Alfisol

A long-term experiment was conducted to evaluate the effect of integrated use of organic and inorganic sources of nutrients on soil quality and its relation to finger millet yield under two predominant crop rotations viz., groundnut–finger millet and finger millet monocropping in hot moist semiarid rainfed Alfisol soils in South India. Two experiments were laid out separately for each cropping system in a randomized complete block design with five treatments individually with FYM and maize residue-based combinations viz., Control (T1), FYM @ 10t ha ^?1 or Maize residue (MR) @ 5t ha ^?1 (T2), farm yard manure (FYM) @ 10t ha ^?1 or Maize residue (MR) @ 5t ha ^?1 + 50% RDF (Recommended Fertiliser Dose) N, P₂O₅ &; K₂O (T3), FYM @ 10t ha ^?1 or Maize residue (MR) @ 5t ha ^?1 + 100% RDF N,P₂O₅ &; K₂O (T4), Recommended N, P₂O₅ &; K₂O (T5). Thus, four sets of nutrient management systems were evaluated. The results showed that farm yard manure or maize residue application in combination with recommended dose of fertilizer significantly improved the soil physical, chemical, and biological properties compared to control and application of inorganic fertilizers alone. Based on evaluation of 19 soil quality parameters under each of the four nutrient management systems, the common key soil quality indicators emerged out were: organic C (OC), available nitrogen (N), available sulfur (S), and mean weight diameter (MWD) of soil aggregates. A significant correlation between the finger millet yield and the relative soil quality indices (RSQI) indicates the importance of soil quality in these semiarid Alfisol soils. The results and the methodology adopted in the present study could be of importance in improving the soil quality not only for the region of the study, but also in other identical soils and cropping systems across the world.     

Enhanced nutrient and rainwater use efficiency in maize and soybean with secondary and micronutrient amendments in the rainfed semi-arid tropics

In view of widespread deficiencies, a long-term experiment was started at the International Crops Research Institute for the Semi-Arid Tropics, Patancheru, India in 2007 to identify economically efficient application strategy (full or 50% dose every or every second year) of sulphur (S) (30 kg ha^?1), boron (B) (0.5 kg ha^?1) and zinc (Zn) (10 kg ha^?1). During the fourth year in 2010, balanced fertilization through adding S, B and Zn increased maize grain yield by 13–52% and soybean yield by 16–28% compared to nitrogen (N) and phosphorus (P) fertilization alone. Balanced nutrition increased N and P uptake, utilization and use efficiency for grain yield and harvest index indicating improved grain nutritional quality. The N, P plus 50% of S, B and Zn application every year recorded highest crop yields and N and P efficiencies indices and increased rainwater use efficiency with a benefit:cost ratio of 11.9 for maize and 4.14 for soybean. This study showed the importance of a deficient secondary nutrient S and micronutrients B, Zn in improving N and P use efficiency while enhancing economic food production.     

Improved Nutrient Uptake and Growth of Maize in Response to Inoculation with Thiobacillus and Mycorrhiza on an Alkaline Soil

Most plant nutrients are optimally available when soil pH is close to neutral. In this experiment the effects of Thiobacillus and Mycorrhiza on nutrient uptake and grain yield of maize were studied on an alkaline soil as a factorial experiment with randomized complete blocks design. Treatments consisted of Mycorrhiza fungi (M): inoculated (m₁) and noninoculated (m₀), Thiobacillus (T): inoculated (t₁) and noninoculated (t₀), and sulfur (S) (S₀, S₁: 250, and S₂: 500 kg ha^?1). Inoculation of Mycorrhiza, Thiobacillus, and S application decreased soil pH and increased grain yield and seed oil content. The lowest soil pH and the greatest S content were obtained from the combination of Thiobacillus and 500 kg ha^?1 S. Inoculation of Thiobacillus and S application significantly decreased root colonization. The greatest iron (Fe) content was in the combination of Mycorrhiza inoculation and 500 kg ha^?1 S. Grain P content significantly increased with Mycorrhiza inoculation and S application. The greatest grain yield obtained from combination of Thiobacillus with 500 kg ha^?1 S.     

Ryegrass forage yield and quality response to sulfur and nitrogen fertilizer on coastal plain soil

Abstract

Sulfur (S) deficiency has been reported in some upland soils of the southern United States and S application has improved forage quality on the low‐S soils. A field experiment was conducted for three years to determine ryegrass (Lolium multiflorum L.) dry matter yield and forage quality response to S fertilization. Prilled elemental S was applied each year at two rates (0 and 45 kg S/ha) in combinations with three rates of nitrogen (N) (168, 224, and 280 kg/ha). Wet depositions of S in rain were monitored over the seasons. Sulfur fertilization generally did not increase seasonal dry matter yield and plant uptake of S. Nitrogen application generally increased dry matter yield and protein content during the season. Averaged over the three‐year period, however, forage yield and S uptake increased from 7.7 to 10.5 Mg/ha and 13.9 to 18.8 kg/ha, respectively, as N fertilization increased from the lowest to highest treatment rates. Forage dry matter for each harvest ranged from 0.6 to 2.2 Mg/ha, while S, protein, in vitro dry matter digestibility (TVDMD), and N/S ratio tended to decline seasonally from 2.5 to 1.8, 266 to 142, and 795 to 716 g/kg, and 17.8 to 11.9, respectively. Sulfur input from rainfall was small with a three‐year average of 5.8 kg/ha (±0.64 SE). In some locations of the southern United States, S may not be limiting even when applying high rates of N to high‐yielding forages which annually remove large quantities of S. Because of the lack of yield response from S application and low inputs of S from wet deposition, S from sources other than rainfall may have been considerable.