Cumulative Effect of Organic and Inorganic Sources of Nutrients on Yield,Nutrients Uptake and Economics by Rice–Wheat Cropping System in Indo-Gangetic Plains of India

ABSTRACT

Field experiments were conducted for 2 years in sandy loam soil, to study the direct effect of organic manures i.e. sewage sludge (SS), vermicompost (VC) and sesbania (SB) and chemical fertilizers on rice (Oryza sativa) and their residual effect on wheat (Triticum aestivum) grown in sequence in winter (Rabi) and summer (Kharif) season during 2015–2016 to 2016–2017 at Varanasi, Uttar Pradesh. Residual effect of organic sources of nutrients as SS, VC and SB were monitored up to fourth crop (II wheat) in sequence applied in conjunction with 75% recommended dose of fertilize (RDF). Among the nutrient sources, the maximum grain yield in I rice (4.89 t ha^?1), II rice (4.95 t ha^?1), was recorded in treatment T₃ (100% RDF with S, Zn, B) whereas in I wheat (4.68 t ha^?1) and II wheat (4.59 t ha^?1), it was recorded in T₄ (customized fertilizer). The maximum straw yield during all four crops was recorded in T₃ (100% RDF with S, Zn, B) in rice and T₄ (customized fertilizer) in wheat crop, which showed 25, 32, 23 and 28% increase over 100% RDF (T₂). Application of 100% RDF along with S, Zn, B and customized fertilizer increased the total uptake of N, P, K, S and B and also in net returns and B:C ratio followed by organic treatments.     

Enhancing nutrient translocation,yields and water productivity of wheat under rice–wheat cropping system through zinc nutrition and residual effect of green manuring

Abstract

Efficient nutrient and water use are two important considerations to obtain good harvests of wheat. This necessitates the development of an effective nutrient management technique that not only increases yield, but simultaneously can save nutrient and water use. In this context, a field experiment was conducted at Indian Agricultural Research Institute, New Delhi, India to evaluate the residual effect of sesbania and rice bean (in-situ), subabul (ex-situ) green manuring and Zinc (Zn) fertilization, using chelated Zn-ethylenediaminetetraacetic acid (Zn-EDTA) on nutrient use, yields and water productivity of wheat under rice–wheat cropping system. Among residual effects of green manure crops and Zn fertilization, sesbania and foliar spray of 0.5% chelated Zn-EDTA at 20, 40, 60 and 80 days after sowing (DAS) recorded significantly higher nutrient content and uptake and yields than other green manure crops and Zn treatments. Residual effect of sesbania saved about 46.5?×?10³ and 30.5?×?10³ L irrigation water per tonne of wheat over subabul and rice bean, respectively. Foliar spray of 0.5% chelated Zn-EDTA at 20, 40, 60 and 80 DAS saved about 55.5?×?10³, 47?×?10³ and 13?×?10³ L irrigation water per tonne wheat over residual effect of 5?kg Zn ha^?1 through chelated Zn-EDTA as soil application, 2.5?kg Zn ha^?1 through chelated Zn-EDTA as soil application + 1 foliar spray of 0.5% chelated Zn-EDTA at flowering and foliar spray of 0.5% chelated Zn-EDTA at active tillering?+?flowering?+?grain filling, respectively. Correlation analysis showed positive correlation between Zn uptake and grain yield.     

大豆叶片对多效唑的吸收、运转和分配

研究大豆叶片对~3H-MET的吸收、运转、分配规律及MET对大豆吸收~(32)P的影响表明,~3H-MET叶面施用很快被大豆吸收,施后1小时吸收量占施用量的39.17％,3小时为51.26％,6小时达61.21％,此后随着施用时间的延长。吸收能力逐渐降低,48小时达66.37％;叶片吸收的~3H-MET基本上滞留于原处理部位,占叶片吸收量的97％左右,向植株其它部位输出较少,而且主要向处理叶上部的茎和叶运转。MET叶面喷施能提高大豆植株对~(32)P的吸收和增加单株干重。     

太行山前平原高产农区土壤水分特征及农田节水潜力

根据连续4年对非耕地和田间土壤水分的测定，分析了太行山前平原高产农区土壤水分的变化规律，并根据该区主要作物冬小麦和夏玉米的需水规律，提出了农田节水潜力的两个方面。     

Ammonia volatilization from nitrogen fertilizers surface-applied to corn (Zea mays) and grass pasture (Dactylis glomerata)

Summary The major agronomic concern with NH₃ loss from urea-containing fertilizers is the effect of these losses on crop yields and N fertilizer efficiency. In this 2-year study, NH₃ volatilization from surface-applied N fertilizers was measured in the field, and the effects of the NH₃ losses detected on corn (Zea mays L.) and orchardgrass (Dactylis glomerata L.) yield and N uptake were determined. For corn, NH₄NO₃ (AN), a urea-AN solution (UAN), or urea, were surface-broadcast at rates of 0, 56 and 112 kg N ha^–1 on a Plano silt loam (Typic Argiudoll) and on a Fayette silt loam (Typic Hapludalf). Urea and AN (0 and 67 kg N ha^–1) were surface-applied to grass pasture on the Fayette silt loam. Significant NH₃ losses from urea-containing N sources were detected in one of four corn experiments (12%–16% of applied N) and in both experiments with grass pasture (9%–19% of applied N). When these losses occurred, corn grain yields with UAN and urea were 1.0 and 1.5 Mg ha^–1, respectively, lower than yields with AN, and orchardgrass dry matter yields with urea were 0.27 to 0.74 Mg ha^–1 lower than with AN. Significant differences in crop N uptake between N sources were detected, but apparent NH₃ loss based on N uptake differences was not equal to field measurements of NH₃ loss. Rainfall following N application markedly influenced NH₃ volatilization. In corn experiments, NH₃ loss was low and yields with all N sources were similar when at least 2.5 mm of rainfall occurred within 4 days after N application. Rainfall within 3 days after N application did not prevent significant yield reductions due to NH₃ loss from urea in grass pasture experiments.     

Tillage and mulch effects on soil physical environment, root growth, nutrient uptake and yield of maize and wheat on an Alfisol in north-west India

Field experiments were conducted for 6 years on a silty clay loam to study the effect of soil management on soil physical properties, root growth, nutrient uptake and yield of rainfed maize (Zea mays L.) and wheat (Triticum aestivum L.) grown in a sequence. Treatments were: no-tillage (NT), NT+pine needle mulch at a rate of 10 t ha⁻¹ (NT+M), conventional tillage (CT), CT+pine needle mulch at a rate of 10 t ha⁻¹ (CT+M) and deep tillage (DT). The soil is classified as a Typic Hapludalf and has compact sub-surface layers. The NT treatment increased the bulk density of the surface layer but this problem was not observed in the no-tilled treatment having mulch at the surface (NT+M). The CT+M and NT+M treatments favourably moderated the hydro-theregime resulting in greater root growth, nutrient uptake and grain yields of maize and wheat. The DT treatment, imposed only once, at the beginning of the study, also enhanced root growth and grain yields. The yields were similar to the mulched treatments for maize and somewhat less than the mulched treatments for wheat. Mulched treatments generally showed significantly greater total uptake of N, P and K than corresponding unmulched ones. Since NT+M was comparable to CT for maize and superior for wheat, the latter is preferable since it does not require ellaborate tillage.     

Responses by iron-efficient and inefficient oat cultivars to inoculation with siderophore-producing bacteria in a calcareous soil

Rhizosphere bacteria may enhance plant uptake of Fe by producing siderophores that chelate sparingly soluble Fe³⁺ in calcareous soils. To evaluate the extent to which plants benefit from colonization of the roots by prolific siderophore-producing bacteria, we inoculated two oat cultivars with six strains of bacteria that produced high concentrations of siderophores under Felimiting conditions in vitro. Oat cv Coker 227, an Fe-efficient cultivar, which produces the phytosiderophore avenic acid, and cv TAM 0-312, and Fe-inefficient cultivar, which does not produce the phytosiderophore, were grown in a calcareous soil (Weswood silt loam) on a light bench in the laboratory. Half of the plants were fertilized with a nutrient solution containing 5 mM Fe and half with a nutrient solution containing no Fe. After 6 weeks of growth, we compared colonization of the roots by the inoculant bacteria and the dry weight and Fe content of roots and shoots. Three species of Pseudomonas colonized the roots of both oat cultivars in high numbers (10⁶ cells g^-1 root dry weight), whereas the remaining bacteria colonized the roots in substantially lower numbers (10⁴ cells g^-1 root dry weight). Plants fertilized with 5 mM Fe were larger and supported greater numbers or rhizosphere bacteria per gram of root than plants not supplied with Fe. Comparisons of the Fe content and dry weight of roots and shoots revealed few significant differences between inoculated and uninoculated plants, or among the plants inoculated with the different strains of siderophore-producing bacteria. The differences that were observed revealed no consistent response to inoculation. We conclude that inoculation of the roots of the two oat cultivars with bacteria that produce high concentrations of siderophores in response to an Fe deficiency had little or no effect on Fe acquisition by the plants.     

Effects of aerobic conditions in the rhizosphere of rice on the dynamics and availability of phosphorus in a flooded soil – A model experiment

The secretion of O₂ by rice roots results in aerobic conditions in the rhizoshere compared to the bulk flooded soil. The effect of this phenomenon on the adsorption/desorption behavior and on the availability of phosphorus (P) in a flooded soil was investigated in a model experiment. An experimental set‐up was developed that imitates both O₂ release and P uptake by the rice root. The results showed that O₂ secretion significantly reduced P adsorption/retention and increased P desorption/release in the “rhizosphere” soil, compared to the anaerobic bulk soil. The P uptake by an anion exchange resin from both unfertilized and P‐amended soil was significantly increased. The results confirm that the O₂ secretion is an important mechanism to enhance P availability and P uptake of rice under flooded conditions, where the “physico‐chemical” availability of P in the anaerobic bulk soil is strongly reduced. The decrease of P availability in the P‐amended flooded bulk soil was mainly associated with the almost complete transformation of the precedingly enriched Al‐P fraction into Fe‐bound P with extremely low desorption/release characteristics during the subsequent flooding.     

Influence of green manuring with Sesbania rostrata and Aeschynomene afraspera or urea on dynamics and uptake of nutrients by wetland rice

Nutrient concentrations in the soil and crop uptake from incorporated green manure and urea in flooded rice was studied in field experiments. Release of plant-available nitrogen (NH₄ ⁺-N) from green manure was slightly delayed compared with that from prilled urea (PU) because Sesbania rostrata L. and Aeschynomene afraspera L. released the N gradually after their decomposition, whereas N became available immediately after PU application. Exchangeable NH₄ ⁺-N concentration in soil peaked at 163 mg kg^–1 in the transplanted rice (TPR) and 198 mg kg^—1 in broadcast-seeded rice (BSR) at 0 and 1 week after PU application. Broadcast-seeded rice depleted NH₄ ⁺-N faster than did TPR because of the crop‘s vigorous growth in the former during the early stage. Soil solution NH₄ ⁺-N followed a similar trend to that of soil NH₄ ⁺-N. Incorporation of S. rostrata and A. afraspera increased the concentration of P, K⁺, Fe²⁺ and Mn²⁺ in soil solution more than did the application of PU. However, zinc concentration decreased in all treatments. Both PU and green manure increased the N status of the rice plants and enhanced the uptake of P, K, Fe, Mn and Zn by the rice crop. This suggests that application of green manures improves the uptake of these nutrients by the crop. The highest apparent N recovery was obtained with PU followed by green manure. Received: 11 November 1996