Nutrient Uptake and Apparent Balances for Rice-Wheat Sequences. III. Potassium

ABSTRACT

Potassium (K) nutrition of rice-wheat (RW) systems of the Indo-Gangetic Plain (IGP) of South Asia is important because of its role in productivity and the large quantities of this macronutrient that are extracted by such intensive cropping systems. Field experiments on the RW cropping sequence were conducted at three locations in Bangladesh with three soil types. Two fertilizer doses—farmers' practice (FP) and soil-test based (STB)—of nitrogen (N), phosphorus (P), K and other nutrients were combined with mungbean or maize as a third crop. The objective of the experiments was to detect K deficiency, if any, in rice, wheat, mungbean, and maize, and to compare the FP- and STB-based sequences in terms of the K nutrition of those crops and the apparent K balance in soil. Frequent K deficiency was observed in rice and wheat at all sites, especially at Ishwordi, while maize was less affected and mungbean not deficient. There was a significant effect of fertilizer on K uptake by maize, mungbean, and rice, but little effect of the retention of mungbean residue on K uptake by crops at any site. Mean annual system-level K uptake was greatest at Ishwordi (126–239 kg ha^?1) and least at Joydebpur (64–116 kg ha^?1). The majority of K uptake was in straw and the proportion in grain varied little across sites (range: 11%–29%). There were large negative apparent K balances in all treatments at all sites (range: ?25–212 kg ha^?1), with the greatest at Ishwordi and the smallest at Joydebpur. Soil K balance responded differently to the retention of residues across soils, and positive effects could be observed on clayey soils. Long-term experiments will be required to monitor soil and plant K dynamics under various fertilizer and residue management of crops in RW systems of the IGP.     

Nutrient Uptake and Apparent Balances for Rice-Wheat Sequences. II. Phosphorus

ABSTRACT

Phosphorus (P) nutrition of the rice-wheat (RW) systems of the Indo-Gangetic Plain of South Asia has become important due to the alternate flooding and drying cycles of this crop rotation. Field experiments on the RW cropping sequence were conducted at three locations of Bangladesh on three soil types. Two fertilizer doses—farmers' practice (FP) and soil-test based (STB), containing recommended amounts of P, nitrogen (N), potassium (K), and other nutrients—were compared with mungbean or maize as a third crop. The objective of the experiments was to detect P deficiency, if any, in rice, wheat, mungbean, and maize, and to compare the FP and STB doses of fertilizers in rice-wheat-mungbean and rice-wheat-maize sequences under two mungbean management practices (residue removed or retained) and one maize management practice (residue removed) in terms of P nutrition of those crops and annual system-level P removal and apparent P balance in the soil. The apparent P balance was negative with the FP dose (?1 to ?9 kg ha^?1 for mungbean sequences at Joydebpur and Nashipur) and there was soil P accumulation under both the STB dose (9–49 kg ha^?1) and zero N control (13–50 kg ha^?1) across sites. The effect of maize or mungbean as the pre-rice crop on the apparent P balance of various RW sequences was not significant. Phosphorus deficiency occurred at all sites in wheat and maize, and at Ishwordi in rice, suggesting that P fertilizer recommendations need to be revised for RW systems in Bangladesh. The results also suggest that long-term monitoring for P concentration, uptake, and balance would be necessary for improving not only the productivity and sustainability of this system but also the fertilizer P-use efficiency.     

Role of crop diversification and integrated nutrient management in resilience of soil fertility under rice-wheat cropping system

A field study conducted for two crop cycles of five cropping systems supplied with six nutrient combinations at the Indian Agricultural Research Institute, New Delhi indicated that the cropping systems having a legume increased organic C content over initial level by 0.02?–?0.05%, available N by 3.5?–?14.1?kg ha^???1, whereas the rice-wheat cropping system resulted in a reduction in organic C and available N over initial level by 0.05% and 1.5?kg ha^???1, respectively after 2 years of study. Rice-potato-mungbean cropping system resulted in a negative balance of available P and rice-clover cropping system had a negative balance of both available P and available K content in soil and thus call for adequate P and K fertilization. Application of P and K helped in building up their content in soil; NPK?+?FYM showed the highest increase in organic C, available N, available P and available K content in soil. These results suggest the inclusion of a legume in a cropping system for maintaining organic C and available N in soil and adequate P and K fertilization for arresting the depletion of available P and K content in soil. Integrated nutrient management is one of the best methods for resilience of soil fertility under rice-wheat cropping system.     

Nutrient Uptake and Apparent Balances for Rice-Wheat Sequences. I. Nitrogen

ABSTRACT

Nitrogen (N) nutrition of the rice-wheat (RW) systems of the Indo-Gangetic Plain is important for sustaining the region's productivity and food needs. Soil N plays an important role in regulating the supply of N to plants. Monitoring plant concentrations, uptake, and balance of N assist in our understanding of plant and soil N status and in devising N-fertilizer strategies for both individual crops and a cropping system. Field experiments with rice-wheat-mungbean and rice-wheat-maize annual cropping sequences were conducted at Joydebpur, Nashipur, and Ishwordi in Bangladesh, which differ in their soils and climates. The experiments compared three pre-rice treatments (mungbean residues retained, mungbean residues removed, and maize residues removed), supplying each with two fertilizer levels (soil-test based, or STB, and farmers' practice, or FP). Zero N (control) treatments were included, with all other nutrients applied as STB or FP. The objectives were to detect N deficiency, if any, in the component crops, and to determine the changes in soil N fertility, plant N uptake, and soil N balance for various RW sequences. There was a significant decrease in mineral N in the topsoil (0–15 cm) of the +N mungbean and maize-residues removed treatments at Ishwordi, and a generally significant but less marked decline under the same treatments at Nashipur. Wheat and maize crops suffered from N deficiency ranging from 33% to 95% each year, at all sites, but deficiency in rice and mungbean was minimal. Annual system-level N uptake across sites ranged from 89 kg ha^?1 for the control to 239 kg ha^?1 for sequences containing maize with N. There were significant linear relationships between total system productivity (TSP) and annual N application and between TSP and annual system-level N uptake. Considering no N loss through the system, N fertilizer resulted in a positive N balance that ranged between 24–190 kg ha^?1 compared with a negative balance of between 40–49 kg ha^?1 without it. However, if a 30% N loss was assumed, N balances were reduced to between ?37–62 kg/ha^?1 for N-containing treatments, and to between ?64–55 kg/ha^?1 for the control treatments. Further research is needed to understand N depletion and replenishment and to sustain the productivity of the RW system.     

System productivity,nutrient use efficiency and apparent nutrient balance in rice-based cropping systems

A 2-year field experiment was conducted to assess system productivity, nutrient use efficiency and apparent balances of phosphorus (P) and potassium (K) in diversified rice-based cropping systems at Gazipur, Bangladesh. Four cropping systems: wheat–fallow–rice, maize–fallow–rice, potato–fallow–rice and mustard–fallow–rice in main plots and four nutrient combinations: NPK, NK, NP and PK in sub-plots were arranged in a split-plot design with three replications. Receiving the NPK treatment, all the component crops gave the highest yield, and omission of N from fertilizer package gave the lowest yield. The maize–rice system removed the highest amount of N (217 kg ha^?1), P (41 kg ha^?1) and K (227 kg ha^?1) followed by wheat–rice, potato–rice and the least in mustard–rice system. The wheat–rice and maize–rice system showed negative K balance of –35.5 and –60.4 kg ha^?1 in NPK treatment, while potato–rice system showed a positive K balance of 31.0 kg ha^–1 with NPK treatment. The N, P and K uptake and apparent recovery by the test crops may be used for site-specific nutrient management. The K rates for fertilizer recommendation in wheat and maize in Indo-Gangetic plain need to be revised to take account for the negative K balance in soil.     

Continuous Cropping,Fertilization, and Organic Manure Application Effects on Potassium in an Alfisol under Arid Conditions

Effects of continuous cropping and addition of organic manures (farmyard manure, FYM, and groundnut shells, GNS) along with inorganic fertilizers on nonexchangeable potassium (K) release kinetics in a K-deficient Alfisol were studied in a 20-year manurial experiment under arid conditions. There was a depletion in available K under continuous cropping without K input (control) as compared to other treatments such as 100% nitrogen–phosphorus–potassium (NPK), 50% NPK + 4 metric tons (MT) groundnut shells ha^?1, 50% NPK + 4 MT FYM ha^?1, and 100% organic (i.e., 5 MT FYM ha^?1). Over 20 years of cropping without K input, available K was reduced from 155 kg ha^?1 (in 1985) to 82 kg ha^?1 (in 2005), showing a negative balance of 73 kg ha^?1. Soil in control plots showed available K in the deficient range (<50 mg kg^?1), whereas four other fertilizer and manurial treatments were greater than the critical limit. Considerable improvements in nonexchangeable K-release parameters such as step K and cumulative K release were observed in manured plots over control. Parabolic diffusion and first-order kinetic equations explained K release from soils. Potassium-release rates were drastically reduced in control plots, and there were increased release rates with continuous addition of manures. Results suggest that soils with groundnut shells or FYM (4 MT ha^?1) along with 50% inorganic fertilizer additions could maintain greater K release rates after 20 years of cropping as compared to cropping without K input.     

Growth and yield of lowland rice as affected by integrated nutrient management and cultivation method under alternate wetting and drying water regime

The effects of integrated nutrient management, cultivation method, and variety on root and shoot growth, grain yield and its components of lowland rice under alternate wetting and drying (AWD) irrigation were evaluated. Treatments included were three varieties (Pathumthani 1, RD57, and RD41), three cultivation methods [dry direct seeding, wet direct seeding, and transplanting], and three nutrient combinations [100% NPK (160?kg ha^?1), 50% NPK (80?kg ha^?1) + 50% FYM (5 t ha^?1), and 100% FYM (10 t ha^?1)] under AWD. Root dry matter of RD41 and RD57 was reduced by 12–25% at the 100% NPK and 100% FYM compared with the 50% NPK + 50% FYM. Panicle number, panicle length, and 1000-grain weight were higher at the 50% NPK + 50% FYM. Application of the 50% NPK + 50% FYM could be a feasible option under AWD irrigation; however, benefits may vary with varieties and cultivation methods.     

Root Growth and Soil Water Dynamics in Relation to Inorganic and Organic Fertilization in Maize–Wheat

Agricultural productivity is increasingly becoming dependent upon soil fertility, which is generally thought to be supplemented through the application of nutrients mainly through inorganic fertilizers. The present study aims to characterize the soil physical environment in relation to long-term application of farmyard manure (FYM) and inorganic fertilizers in a maize–wheat cropping system. The treatments in both the maize and wheat systems included a control (without any fertilizer or FYM), FYM (farmyard manure at 20 t ha^?1), N₁₀₀ (nitrogen at 100 kg ha^?1), N₁₀₀P₅₀ (nitrogen and phosphorus at 100 and 50 kg ha^?1), and N₁₀₀P₅₀K₅₀ (nitrogen, phosphorus, and potash at 100, 50, and 50 kg ha^?1). The treatments were replicated four times in a randomized complete block design in sandy loam soil. The root mass density in surface layers of both the crops was lower in FYM and higher in inorganic fertilizer plots. The root length density was found to be highest in FYM-treated plots and lowest in control plots. The periodic soil matric suction during wheat following maize remained highest in FYM plots followed by that in N₁₀₀ plots in all the layers. The soil water storage of wheat at harvest (rice–wheat) was highest (21.1 cm) in control and lowest (17.8 cm) in FYM-treated plots. The soil water status, root growth, and crop performance improved with balanced fertilization.     

Fertilizer micro-dosing increases crop yield in the Sahelian low-input cropping system: A success with a shadow

Over the years, a scarcity of information on nutrient gains or losses has led to overemphasis being placed on crop yields and economic income as the direct benefits from fertilizer micro-dosing technology. There is increasing concern about the sustainability of this technology in smallholder Sahelian cropping systems. This study was designed in the 2013 and 2014 cropping seasons to establish nutrient balances under fertilizer micro-dosing technology and their implications on soil nutrient stocks. Two fertilizer micro-dosing treatments [2 g hill^?1 of diammonium phosphate (DAP) and 6 g hill^?1 of compound fertilizer Nitrogen-Phosphorus-Potassium (NPK) (15-15-15)] and three rates of manure (100 g hill^?1, 200 g hill^?1 and 300 g hill^?1) and the relevant control treatments were arranged in a factorial experiment organized in a randomized complete block design with three replications. On average, millet (Pennisetum glaucum (L.) R.Br.) grain yield increased by 39 and 72% for the plots that received the fertilizer micro-dosing of 6 g NPK hill^?1 and 2 g DAP hill^?1, respectively, in comparison with the unfertilized control plots. The average partial nutrients balances for the two cropping seasons were ?37 kg N ha^?1yr^?1, ?1 kg P ha^?1yr^?1 and ?34 kg K ha^?1yr^?1 in plots that received the application of 2 g DAP hill^?1, and ?31 kg N ha^?1yr^?1, ?1 kg P ha^?1yr^?1 and ?27 kg K ha^?1yr^?1 for 6 g NPK hill^?1. The transfer of straw yields accounted for 66% N, 55% P and 89% K for removal. The average full nutrient balances for the two cropping seasons in fertilizer micro-dosing treatments were ?47.8 kg N ha^?1 yr^?1, ?6.8 kg P ha^?1 yr^?1 and ?21.3 kg K ha^?1 yr^?1 which represent 7.8, 24.1 and 9.4% of N, P and K stocks, respectively. The nutrient stock to balance ratio (NSB) for N decreased from 13 to 11 and from 15 to 12 for the plots that received the application of 2 g DAP hill^?1 and 6 g NPK hill^?1, respectively. The average NSB for P did not exceed 5 for the same plots. It was concluded that fertilizer micro-dosing increases the risk of soil nutrient depletion in the Sahelian low-input cropping system. These results have important implications for developing an agro-ecological approach to addressing sustainable food production in the Sahelian smallholder cropping system.     

Effect of phosphorus management in rice–mungbean rotations on sandy soils of Cambodia

Nitrogen (N) and phosphorus (P) deficiencies are key constraints in rainfed lowland rice (Oryza sativa L.) production systems of Cambodia. Only small amounts of mineral N and P or of organic amendment are annually applied to a single crop of rainfed lowland rice by smallholder farmers. The integration of leguminous crops in the pre‐rice cropping niche can contribute to diversify the production, supply of C and N, and contribute to soil fertility improvement for the subsequent crop of rice. However, the performance of leguminous crops is restricted even more than that of rice by low available soil P. An alternative strategy involves the application of mineral P that is destined to the rice crop already to the legume. This P supply is likely to stimulate legume growth and biological N₂ fixation, thus enhancing C and N inputs and recycling N and P upon legume residue incorporation. Rotation experiments were conducted in farmers' fields in 2013–2014 to assess the effects of P management on biomass accumulation and N₂ fixation (δ¹⁵N) by mungbean (Vigna radiata L.) and possible carry‐over effects on rice in two contrasting representative soils (highly infertile and moderately fertile sandy Fluvisol). In the traditional system (no legume), unamended lowland rice (no N, + 10 kg P ha^?1) yielded 2.8 and 4.0 t ha^?1, which increased to 3.5 and 4.7 t ha^?1 with the application of 25 kg ha^?1 of urea‐N in the infertile and the moderately fertile soil, respectively. The integration of mungbean as a green manure contributed up to 9 kg of biologically fixed N (17% Nfda), increasing rice yields only moderately to 3.5–4.6 t ha^?1. However, applying P to mungbean stimulated legume growth and enhanced the BNF contribution up to 21 kg N ha^?1 (36% Nfda). Rice yields resulting from legume residue incorporation (“green manure use”–all residues returned and “grain legume use”–only stover returned) increased to 4.2 and 4.9 t ha^?1 in the infertile and moderately fertile soil, respectively. The “forage legume use” (all above‐ground residues removed) provided no yield effect. In general, legume residue incorporation was more beneficial in the infertile than in the moderately fertile soil. We conclude that the inclusion of mungbean into the prevailing low‐input rainfed production systems of Cambodia can increase rice yield, provided that small amounts of P are applied to the legume. Differences in the attributes of the two major soil types in the region require a site‐specific targeting of the suggested legume and P management strategies, with largest benefits likely to accrue on infertile soils.     

Long-term nitrogen balance for pearl millet (Pennisetum glaucum L.) in an acid sandy soil of Niger

On acid sandy soils of Niger (West Africa) fertilizer N recovery by pearl millet (Pennisetum glaucum L.) is often more than 100 per cent in years with normal or above average rainfall. Biological nitrogen fixation (BNF) by N₂-fixing bacteria may contribute to the N supply in pearl millet cropping systems. For a long-term field experiment comprising treatments with and without mineral fertilizer (F) and with and without crop residue application (CR) a N balance sheet was calculated over a period of six years (1983-1988). After six years of successive millet cropping total N uptake (36-77 kg N ha^?1 yr^?1) was distinctly higher than the amount of fertilizer N applied (30 kg N ha^?1 yr^?1). The atmospheric input of NH₄-N and NO₃-N in the rainwater was about 2 kg N ha_?1 yr^?1, 70 % in the form of NH₄-N. Gaseous NH₃ losses from urea (broadcast, incorporated) were estimated from other experiments to amount to 36 % of the fertilizer N applied. Nitrogen losses by leaching (15 to > 25 kg N ha^?1 yr^?1) were dependent on the treatment and on the quantity and distribution of single rainfall events (>50 mm). Decline in total soil N content (0-60 cm) ranged from 15 to 48 kg N ha^?1 yr^?1. The long-term N balance (1983-1988) indicated an annual net gain between 6 (+CR-F) and 13 (+CR+F) kg N ha^?1 yr^?1. For the control (-CR-F) the long-term N balance was negative (10 kg N ha^?1 yr^?1). In the treatment with crop residues only, the N balance was mainly determined by leaching losses, whereas in treatments with mineral fertilizer application the N balance depended primarily on N removal by the millet crop. The annual net gain in the N balance increased from 7 kg ha^?1 with mineral fertilizer to 13 kg ha^?1 in the combination mineral fertilizer plus crop residues. In both the rhizosphere and the bulk soil (0-15 cm), between 9 and 45% of the total bacterial population were N₂-fixing (diazotrophic) bacteria. The increased N gain upon crop residue application was positively correlated with an increase in the number of diazotrophic and total bacteria. The data on bacterial numbers suggest that the gain of N in the longterm N balance is most likely due to an N input by biological nitrogen fixation. In addition, evidence exists from related studies that the proliferation of diazotrophs and total bacteria in the rhizosphere due to crop residue application stimulated root growth of pearl millet, and thus improved the phosphorus (P) acquisition in the P deficient soil.     

Residual effects of nitrogen sources,sulfur and boron levels on mungbean (Vigna radiata) in a sunflower (Helianthus annuus)–mungbean system

Field experiments were conducted during spring–rainy (kharif) seasons of 2005 and 2006 on a sunflower–mungbean cropping system at the research farm of the Division of Agronomy, Indian Agricultural Research Institute (IARI), New Delhi, India. The objectives of this study were to investigate the residual effect of nitrogen sources, sulfur and boron levels applied to sunflower on productivity, nutrient concentrations and their uptake by the succeeding mungbean crop in a sunflower–mungbean cropping system. The experiment with 19 treatments was laid out in factorial randomized block design for both sunflower and mungbean. The residual effects of nutrients applied to sunflower were significant on the succeeding mungbean crop in terms of biometric parameters, yield attributing characters, seed yield and soil nutrient status. The highest mungbean seed yield (961.2 kg ha^?1) was produced with 50 kg ha^?1 sulfur application to the preceding sunflower crop, which was significantly (p < 0.05) higher than with 0 and 25 kg sulfur ha^?1. The concentrations and uptake of nitrogen, sulfur and boron were also greater in the succeeding mungbean crop due to the residual effects of nutrients applied to the preceding sunflower crop. The soil nutrient status before and after mungbean indicated that the available nitrogen and sulfur were higher due to application to the preceding crop, while available boron after mungbean was even higher than after sunflower due to its slow release and static nature in the soil.     

Long-Term Fertilization Effects on Rice Productivity and Nutrient Efficiency in Korean Paddy

ABSTRACT

Long-term fertilization tests evaluated rice (Oryza sativa) productivity in relation to application of nitrogen (N)-phosphorus (P)-potassium (K) (120-34.9-66.7 kg ha^{? 1}, respectively) during 1967–1972 and N-P-K (150-43.7-83.3 kg ha^{? 1}, respectively) during 1973–2000. The comparison treatments (NP, PK, and NK) and the control (not fertilized) were selected for calculating nutrient efficiency. Rice grain yield increased at a 17.78 kg ha^{? 1} yr^{? 1} in the control, mainly due to development of improved cultivars. Phosphorus management was found to be important for indigenous fertility and rice productivity in this paddy soil. Yield increased significantly with P fertilization. Without N fertilization (PK), rice productivity increased 56.85 kg ha^{? 1} yr^{? 1} from 62% of NPK at the initial stage to 74% after passing 34 years, which might be affected by increasing biological N fixation with P accumulation in soil. In NK treatment, rice yield increased at a relatively low rate (37.82 kg hr^{? 1} yr^{? 1}) from the same rice productivity with that of NPK in 1967 to 91% after 34 years. In comparison, yield increased at a high rate (62.82 kg hr^{? 1} yr^{? 1}) without K fertilization (NP) from ca. 90% of NPK and might exceed the yield of NPK after 64 years of long-term fertilization. Therefore, K fertilization level might be readjusted after long-term fertilizing in paddy soil.     

Effect of different fertilization modes on soil organic carbon sequestration in acid soils

ABSTRACT

A meta-analysis of 297 treatment data from the Vezaiciai Branch of the Lithuanian Research Centre for Agriculture and Forestry long-term field experiment published from 2006 to 2015 was used to characterize the changes in SOC under different fertilization treatments and residue management practices in Lithuania’s acid soil. A meta-analysis was performed to quantify the relative annual change (RAC) of SOC content and the average RAC rate of SOC under four fertilization modes (farmyard manure (FYM) (40?t?ha^?1)); alternative organic fertilizers (in the manure background (40?t?ha^?1)); FYM (60?t?ha^?1); alternative organic fertilizers (in the manure background (60?t?ha^?1)) in two soil backgrounds (naturally acid and limed soil). The average RAC under four fertilization modes was 1.46 g?kg^?1?yr^?1, indicating that long-term fertilization had considerable SOC sequestration potential. Incorporation of alternative organic fertilizers in unlimed soil showed negative effects (?0.39 and ?0.66 g?kg^?1?yr^?1) in the observed long-term experiment. The RAC in the limed soil with incorporated organic fertilizers (FYM and alternative organic fertilizers), compared to the control, and varied from 0.25 g?kg^?1?yr^?1 in the treatment with incorporated alternative organic fertilizers (in the manure background (40?t?ha^?1)) to 0.71 g?kg^?1?yr^?1 in the soil with FYM (60?t?ha^?1). In this study, the average RAC rate of SOC under organic fertilization treatments in limed soil (5.07–6.54%) was longer than organic fertilization in unlimed soil (2.11–3.49%), which might be attributed to the application of organic manure that would result in a slow release of fertilizer efficiency. Our results indicate that the application of manure (40 or 60?t?ha^?1) showed the greatest potential for C sequestration in agricultural soil and produced the longest SOC sequestration duration.     

Agronomic evaluation of mulching and iron nutrition on productivity,nutrient uptake,iron use efficiency and economics of aerobic rice-wheat cropping system

Field experiments were carried out during rainy (kharif) and winter (rabi) seasons (June–April) of 2008–2010 at Indian Agricultural Research Institute (IARI), New Delhi, to study the productivity, nutrients uptake, iron (Fe) use-efficiency and economics of aerobic rice-wheat cropping system as influenced by mulching and Fe nutrition. The highest yield attributes, grain and straw yields (5.41 tonnes ha^?1 and 6.56 tonnes ha^?1, respectively) and nutrient uptake in rice was recorded with transplanted and puddled rice (TPR) followed by aerobic rice with Sesbania aculeata mulch. However, residual effect of aerobic rice with wheat straw mulch was more pronounced on yield attributes, grain and straw yields (4.20 and 6.70 tonnes ha^?1, respectively) and nutrient uptake in succeeding wheat and remained at par with aerobic rice with Sesbania mulch. Application of iron sulfate (FeSO₄) at 50 kg ha^?1 + 2 foliar sprays of 2% FeSO₄ was found to be the best in terms of all the yield attributes, grain and straw yield (5.09 and 6.17 tonnes ha^?1, respectively) and nutrient uptake and remained at par with 3 foliar sprays of 2% FeSO₄. Although residual effect of iron application failed to increase the yield attributes, yield and nutrient uptake nitrogen, phosphorus and potassium (N, P, K) except Fe. The highest system productivity, nutrient uptake, gross returns, net returns, B: C ratio and lowest cost of cultivation were recorded with aerobic rice with wheat straw and Sesbania aculeata mulch. Application of FeSO₄ at 50 kg ha^?1 + two foliar sprays of 2% FeSO₄ was found better in respect of system productivity, nutrient uptake, gross returns, net returns, B:C ratio and cost of cultivation in aerobic rice-wheat cropping system. The Fe use efficiency values viz. partial factor productivity (kg grain kg^?1 Fe), agronomic efficiency (kg grain increased kg^?1 Fe applied), agrophysiological efficiency (kg grain kg^?1 Fe uptake), physiological efficiency (kg biomass kg^?1 Fe uptake), apparent recovery (%) utilization efficiency and harvest index (%) of applied Fe were significantly affected due to methods of rice production and various Fe nutrition treatments in aerobic rice and aerobic rice-wheat cropping system.     

Integrated Nutrient-Management Technology for Direct-Seeded Upland Rice (Oryza sativa) in Northwestern Himalayas

Alarming climate change, rainfed upland farming, and low resource-use efficiency of conventional fertilizer management practices are major production constraints detrimental to rice productivity in the northwestern (NW) Himalayas. Recent agronomic intervention of direct-seeded rice (DSR) coupled with suitable rice germplasm well suited to rainfed upland ecosystems in combination with appropriate integrated nutrient-management (INM) technology can enhance the rice productivity in the region. Thus, a field experiment with seven treatments replicated three times in a randomized block design was conducted on INM technology in rainfed upland rice cv. HPR-1156 (Sukaradhan-1) to harness the potential of DSR technology in order to boost rice productivity in the NW Himalayas. Results on INM in direct-seeded upland rice revealed that nitrogen, phosphorus, and potassium (NPK) at 90:45:45 kg ha^?1 + farm yard manure (FYM) at 5 t ha^?1 (oven dry-weight basis) significantly resulted in the greatest magnitude of growth and development (plant height, tillers m^?2) and yield-contributing characters (panicles m^?2, panicle length, grains panicle^?1 and 1000-grain weight), resulting in significantly greatest grain, straw, and biological yield followed by sole use of NPK at 90:45:45 kg ha^?1 and NPK at 60:30:30 kg ha^?1 + FYM at 5 t ha^?1, respectively, in rainfed upland rice. Application of NPK at 90:45:45 kg ha^?1 + FYM at 5 t ha^?1 again resulted in significant improvement in soil organic carbon and available NPK status over other treatments and initial soil fertility status in an acidic Alfisol. Overall, it is inferred that INM technology with judicious use of NPK at 90:45:45 kg ha^?1 + FYM at 5 t ha^?1 in rainfed upland rice under DSR technology can enhance the rice productivity and resource-use efficiency in NW Himalayas.     

Influence of Organic Manures on Soil Characteristics and Yield of Jerusalem Artichoke

ABSTRACT

The objective of this study was to study the influence of three organic manures, farm yard manure (FYM), poultry manure (PLM), and pigeon manure (PGM), on soil physical and chemical properties on tuber yield of Jerusalem artichoke in a newly reclaimed saline calcareous soil. A field experiment was conducted applying the three manures, alone and/or in different combinations. Soils were investigated at surface (0–30 cm) and subsurface (30–60 cm) layers before and after planting, and analyzed for physical and chemical properties. The results indicated that the application of 31.5 kg ha^?1 of PLM+10.5 kg of PGM T7 recorded highest available nitrogen, zinc, copper, and moisture content at the surface layer. The same results were obtained for iron and manganese at both layers. While, applying 21.0 kg ha^?1 FYM+21.0 kg ha^?1 PLM T10 recorded the best treatment for pH, phosphorus, zinc, copper, moisture content, and saturation percentage at the subsurface layer. Applying 21.0 kg ha^?1 PGM + 10.5 kg ha^?1 FYM+10.5 kg ha^?1 PLM T15 recorded the best treatment for organic matter content and bulk density at surface layer and reduced the electrical conductivity and inulin tuber content at both layers. On the other hand, calcium carbonate and sodium adsorption ratio were reduced in both layers by applying 21.0 kg ha^?1 PLM+10.5 kg ha^?1 FYM+10.5 kg ha^?1 PGM T14. The best treatment for tuber nitrogen content and total yield was obtained with applying 42.0 kg ha^?1 PLM T2 only and 31.5 kg ha^?1 FYM+10.5 kg ha^?1 PLM T4, respectively.     

Effect of wheat,legume and legume enriched wheat residue and nitrogen application on soil fertility under rice-wheat cropping system

The field experiments were conducted for two crop years of 1997?–?98 and 1998?–?99 at the Indian Agricultural Research Institute, New Delhi to study the effect of wheat, legume and legume enriched wheat residue (WR) on soil fertility under the rice-wheat cropping system. A rice-wheat cropping system without incorporation of residue depleted organic C over initial level by 0.061%, kjeldahl-N by 0.012%, available P by 0.7?kg ha^???1 and available K by 36?kg ha^???1, whereas incorporation of Sesbania green manure (SGM), mungbean residue (MBR), SGM?+?WR and MBR?+?WR increased organic C over the initial level by 0.071, 0.100, 0.163 and 0.133%, respectively, kjeldahl-N by 0.001, 0.004, 0.001 and 0.005% respectively, available P by 2.7, 5.0, 8.5 and 3.2?kg ha^???1, respectively and available K by 35, 5, 92 and 12?kg ha^???1, respectively in 2 years. As compared with no residue control, incorporation of WR increased organic C by 0.036?–?0.102%, kjeldahl-N by 0.002?–?0.007% and available K by 23?–?45?kg ha^?1, whereas incorporation of SGM and MBR increased organic C by 0.082?–?0.132 and 0.103?–?0.161%, respectively, kjeldahl-N by 0.009?–?0.023 and 0.005?–?0.013%, respectively and available K by 5?–?71 and 4?–?45?kg ha^???1, respectively. Incorporation of WR with SGM and MBR was more effective and increased organic C by 0.121?–?0.224 and 0.125?–?0.194%, respectively, kjeldahl-N by 0.005?–?0.029 and 0.010?–?0.021%, respectively and available K content by 23?–?128 and 11?–?116?kg ha^???1. Nitrogen application to rice also increased organic C, kjeldahl-N, available P and available K content in soil and also increased effects of crop residues. Crop residues had no significant effect on available P content in soil. Incorporation of WR with SGM and MBR with adequate fertilizer-N is, thus, recommended for building up organic C, kjeldahl-N and available K content in soil.     

Improving soil organic carbon pools through inclusion of summer mungbean in cereal-cereal cropping systems in Indo-Gangetic plain

Long-term effect of mungbean inclusion in lowland rice-wheat and upland maize-wheat systems on soil carbon (C) pools, particulate organic C (POC), and C-stabilization was envisaged in organic, inorganic and without nutrient management practices. In both lowland and upland systems, mungbean inclusion increased very-labile C (Cfrac₁) and labile C (Cfrac₂) in surface soil (0–0.2 m). Mungbean inclusion in cereal-cereal cropping systems improved POC, being higher in lowland (107.4%). Lowland rice-based system had higher passive C-pool (11.1 Mg C ha^?1) over upland maize-based system (6.6 Mg C ha^?1) indicating that rice ecology facilitates the stabilization of passive C-pool, which has longer persistence in soil. Organic nutrient management (farmyard manure + full crop residue + biofertilizers) increased Cfrac₁ and carbon management index (CMI) over inorganic treatment. In surface soil, higher CMI values were evident in mungbean included cropping systems in both lowland and upland conditions. Mungbean inclusion increased grain yield of cereal crops, and yield improvement followed the order of maize (23.7–31.3%) > rice (16.9–27.0%) > wheat (lowland 7.0–10.7%; upland 5.4–16.6%). Thus, the inclusion of summer mungbean in cereal-cereal cropping systems could be a long-term strategy to enrich soil organic C and to ensure sustainability of cereal-cereal cropping systems.     

Influence of Soil and Fertilizer Nutrients on Sustainability of Rainfed Finger Millet Yield and Soil Fertility in Semi-arid Alfisols

Productivity of rainfed finger millet in semiarid tropical Alfisols is predominantly constrained by erratic rainfall, limited soil moisture, low soil fertility, and less fertilizer use by the poor farmers. In order to identify the efficient nutrient use treatment for ensuring higher yield, higher sustainability, and improved soil fertility, long term field experiments were conducted during 1984 to 2008 in a permanent site under rainfed semi-arid tropical Alfisol at Bangalore in Southern India. The experiment had two blocks—Farm Yard Manure (FYM) and Maize Residue (MR) with 5 fertilizer treatments, namely: control, FYM at 10 t ha^?1, FYM at 10 t ha^?1 + 50% NPK [nitrogen (N), phosphorus (P), potassium (K)], FYM at 10 t ha^?1 + 100% NPK (50 kg N + 50 kg P + 25 kg K ha^?1) and 100% NPK in FYM block; and control, MR at 5 t ha^?1, MR at 5 t ha^?1 + 50% NPK, MR at 5 t ha^?1 + 100% NPK and 100% NPK in MR block. The treatments differed significantly from each other at p < 0.01 level of probability in influencing finger millet grain yield, soil N, P, and K in different years. Application of FYM at 10 t ha^?1 + 100% NPK gave a significantly higher yield ranging from 1821 to 4552 kg ha^?1 with a mean of 3167 kg ha^?1 and variation of 22.7%, while application of maize residue at 5 t ha^?1 + 100% NPK gave a yield of 593 to 4591 kg ha^?1 with a mean of 2518 kg ha^?1 and variation of 39.3% over years. In FYM block, FYM at 10 t ha^?1 + 100% NPK gave a significantly higher organic carbon (0.45%), available N (204 kg ha^?1), available P (68.6 kg ha^?1), and available K (107 kg ha^?1) over years. In maize residue block, application of MR at 5 t ha^?1 + 100% NPK gave a significantly higher organic carbon (0.39%), available soil N (190 kg ha^?1), available soil P (47.5 kg ha^?1), and available soil K (86 kg ha^?1). The regression model (1) of yield as a function of seasonal rainfall, organic carbon, and soil P and K nutrients gave a predictability in the range of 0.19 under FYM at 10 t ha^?1 to 0.51 under 100% NPK in FYM block compared to 0.30 under 100% NPK to 0.67 under MR at 5 t ha^?1 application in MR block. The regression model (2) of yield as a function of seasonal rainfall, soil N, P, and K nutrients gave a predictability in the range of 0.11 under FYM at 10 t ha^?1 to 0.52 under 100% NPK in FYM block compared to 0.18 under MR at 5 t ha^?1 + 50% NPK to 0.60 under MR at 5 t ha^?1 application in MR block. An assessment of yield sustainability under different crop seasonal rainfall situations indicated that FYM at 10 t ha^?1 + 100% NPK was efficient in FYM block with a maximum Sustainability Yield Index (SYI) of 41.4% in <500 mm, 64.7% in 500–750 mm, 60.2% in 750–1000 mm and 60.4% in 1000–1250 mm rainfall, while MR at 5 t ha^?1 + 100% NPK was efficient with SYI of 29.6% in <500 mm, 50.2% in 500–750 mm, 40.6% in 750–1000 mm, and 39.7% in 1000–1250 mm rainfall in semi-arid Alfisols. Thus, the results obtained from these long term studies incurring huge expenditure provide very good conjunctive nutrient use options with good conformity for different rainfall situations of rainfed semiarid tropical Alfisol soils for ensuring higher finger millet yield, maintaining higher SYI, and maintaining improved soil fertility.