Short‐term (5 years) impact of tillage and residue management practices on physical properties and organic carbon (OC) of a silty clay soil was evaluated in a rice–wheat rotation in the Indo‐Gangetic ...Plains of Bihar. The experiment had three conservation agriculture (CA) practices: one full (direct‐seeded rice (DSR)–no‐tilled wheat (NTW)–no‐tilled mung bean (NTMB); fCA) and two partial (puddled transplanted rice (PTR)–NTW–conventionally tilled mung bean (CTMB); pCA1 and unpuddled transplanted rice (UPTPR)–conventionally tilled potato+maize (CTP + M)–NTMB; pCA2), which were evaluated against full conventional practice (puddled transplanted rice (PTR)–conventionally tilled wheat (CTW); TA). Subsurface compaction reduced and soil aggregation improved under both full and partial CA. Macro‐ and water‐stable aggregates increased to a large extent (26 and 11%, respectively) in full CA and to a lesser extent in partial CA, mostly due to increase in coarse macroaggregate (2–8 mm) contents in the 0–10 and 10–20‐cm depth soil layers. Steady‐state infiltration rate nearly doubled under full CA, with larger pore volume recorded in 10–20 and 20–30‐cm depth soil layers. The CA increased OC associated with all size fractions of aggregates in the surface soil layer (0–10 cm), but a higher amount of C was associated with macroaggregates, indicating relative stabilization of OC in the soil under CA. Change in bulk soil OC was larger in the 0–10‐cm depth soil layer in favour of CA, which also had an 11% increase in OC stock in the 0–30‐cm depth soil layer. Improvement in soil physical condition did not effectively translate into increased rice or wheat yields, but the system productivity increased largely.
Highlights
Conservation agriculture (CA) resulted in 11–12% higher macro‐aggregation compared to conventional practice (CT).
Macro‐ and total pores reduced in the 0–10 cm depth soil layer but increased in the 10–20 cm depth soil layer under CA.
CA resulted in 27–35% higher aggregate‐associated OC content and 11% increase in OC stock at 0–30 cm.
Full/partial CA improved soil physical condition and the productivity of rice–wheat systems in the Indo‐Gangetic Plains.
Soil and water resource management is a serious concern in respect of climate variability to increase soil moisture and fulfil the need of living population and flora and fauna. In the context of ...basin, prioritization of sub-watershed has gained significance in the natural resource management. The study prioritized the sub-watershed of the Sakri basin using a multivariate geomorphometric approach. The basin resulted in the formation of 11 sub-watersheds. Measurement of basic and derived morphometric parameter was considered, and 17 parameters have been taken for ranking and priority of sub-watershed. The morphometric analysis and principal component analysis (PCA) approaches were employed for ranking and prioritization of sub-watershed, based on high correlated parameters. Based on the results of morphometric analysis and PCA, sub-watersheds were categorized in high, medium and low priority. Among a total of 11 sub-watersheds, sub-watershed (SW) 3, 5, 6, 8 and 9 falling under high priority, which accounting to 46.82% of the basin. The high priority sub-watershed is at a higher risk of erosion which needs instantaneous soil and water conservation measures for betterment of basin morphometry and minimizes drought conditions. Results of the two approaches show that morphometric-based prioritization is more reliable and better in decision making for soil and water conservation planning at the sub-watershed level. Overall, these results are highly relevant in planning and developing of suitable soil and water conservation structures for mitigation and prevention in the region.
Climate-smart agriculture (CSA) practices are becoming increasingly important due to their better adaptability to harsh climatic conditions (in general) and the unpredictability of monsoons in India ...(in particular). Conventional rice cultivation (e.g., PTR) involves intensive tilling followed by intensive puddling in standing water that destroys the soil aggregation and depletes carbon pools. Therefore, alternative crop establishment methods need to be devised for the sustainability of system productivity, and the suitabilities of potential oilseeds and pulses need to be tested for cropping intensification in rice-fallow regions. Hence, an ongoing experiment (implemented in 2016) was evaluated to identify the appropriate CSA management practices in restoring soil C and physical health under diversified cropping systems in the rice-fallow system of eastern India. Six tillage and crop establishment methods along with residue management were kept as the main plots zero-till-direct-seeded rice (ZTDSR), conventional-till-DSR (CT-DSR), puddled transplanted rice (PTR), ZTDSR with rice residue retentions (ZTDSRR+), CTDSR with rice residue retention (CTDSRR+), PTR with rice residue retention (PTRR+) while five winter/post-rainy crops (oilseeds and pulses) were raised in a subplot. In the ZTDSRR+ production system, soil macro-aggregate (%), macro-aggregate-associated C, MWD, and GMD of aggregates increased by 60.1, 71.3, 42.1, and 17.1%, respectively, in comparison to conventional tillage practices (PTR). The carbon management index (CMI) was 58% more in the ZTDSRR+ production system compared to PTR. Among the winter crops, chickpeas recorded higher values of soil structural indices and C content. In the PTR production system, system productivity, in terms of rice equivalent yield, was comparable to ZTDSRR+. ZT with residue retention in rice followed by post-rainy/winter pulses led to higher C content and structural stability of the soil. Thus, CSA management practices can improve the crop productivity as well as soil health of rice-fallow production systems of eastern India and comparable agroecotypes of South Asia.
Lysimetric and eddy covariance techniques are commonly used to directly estimate actual crop evapotranspiration (ETa). However, these technologies are costly, laborious, and require skills which make ...in situ ET estimation difficult, particularly in developing countries. With this in mind, an attempt was made to determine ETa and stagewise crop coefficient (Kc) values of transplanted puddled rice using a modified non-weighing paddy lysimeter. The results were compared to indirect methods, viz., FAO Penman–Monteith and pan evaporation. Daily ETa ranged from 1.9 to 8.2 mmday−1, with a mean of 4.02 ± 1.35 mmday−1, and their comparison showed that the FAO Penman–Monteith equation performed well for the coefficient of determination (R2 of 0.63), root mean squared error (RMSE = 0.80), and mean absolute percentage error (MAPE = 13.6 %), and was highly correlated with ETa throughout the crop season. However, the pan evaporation approach was underestimated (R2 of 0.24; RMSE = 0.98; MAPE = 22.13%) due to a consistent pan coefficient value (0.71), vegetation role and measurement errors. In addition, actual Kc values were obtained as 1.13 ± 0.13, 1.27 ± 0.2, 1.23 ± 0.16, and 0.93 ± 0.18 for the initial, crop development, mid-season, and end-season stages, respectively. These estimated crop coefficient values were higher than FAO Kc values. Statistical analysis results revealed that the overall stagewise-derived average Kc values were in line with FAO values, but different from the derived pan Kc values, although found insignificant at a 5% significance level. In addition, water productivity and agro-meteorological indices were derived to evaluate the cultivar performance in this experiment. Therefore, such a methodology may be used in the absence of weighing lysimeter-derived Kc values. The derived regional Kc values can be applied to improve irrigation scheduling under similar agro-climatic conditions.
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•Soil physicochemical and biological properties were used for SQI development.•Major parameters studied were FDA, DHA, MBC, SOC, Av. NPK, AWC, MAS and SPR.•Highest SQI value of 0.90 ...was found in ZTDSR-ZTW at 0-10 cm soil depth.
Rice-wheat cropping system (RWCS) is the most important system occupying around 26 M ha spread over the Indo Gangetic Plains in South Asia and China. Many long-term trials were led to assess the agronomic productivity and economic profitability of various combinations of conservation agricultural (CA) practices (zero tillage, residue management and crop establishment) in RWCS of Eastern Indo-Gangetic Plains (EIGP) of India. The purpose of this study was to investigate the best management practices involving different tillage-based crop establishment and residue retention techniques and their contribution to agricultural system sustainability through improvement in soil health by developing soil quality index (SQI). We have used SQI as an instrument based on physical macro aggregate stability (MAS), available water capacity (AWC) and soil penetration resistance (SPR), chemical soil organic carbon (OC), available N, available P and available K and biological microbial biomass carbon (MBC), fluorescein diacetate (FDA) and dehydrogenase activity (DHA) properties of soil, because these are very useful indicators of soil’s functions for agronomic productivity and soil fertility. Soil properties like MAS, OC, MBC, FDA and DHA were higher by 47, 18, 56, 48 and 53%, respectively, under ZTDSR-ZTW (T7: Zero-till direct seeded rice - Zero-till wheat) than RPTR-CTW (T1: Random puddled transplanted rice - Conventional till broadcasted wheat), at 0-10 cm. CA based treatment T7 also recorded lower SPR (126 N cm-1). SQI for different treatments were calculated by performing principal component analysis based on the total data set method. The higher system rice equivalent yield of 12.41 t ha-1 was observed at SQI value of 0.90 at 0-10 cm and 0.86 at 10-20 cm in T7. It can be concluded that crop residue retention on the surface with zero tillage is beneficial for the sustainability and productivity of the RWCS in EIGP of India.
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•Different crop establishment methods were compared with traditional conventional tillage (CT) in rice-wheat cropping system.•Net returns and benefit cost ratio were increased by 11 ...and 28 % under conservation agriculture (CA) -based systems than CT.•System productivity was at par while earthworm population was two times higher under CA-based production system than CT.•CA-based systems had 15 % less energy input and 14–36 % higher energy productivity than CT.•Direct seeded rice consumed 6.8 % less water and had 56.2 % less methane emission than puddled transplanted rice.
In the eastern Indo-Gangetic Plains (EIGP), conventional rice-wheat system has led to a decline in productivity, input-use efficiency, and profitability. To address these, a four-year field study was conducted to evaluate the performance of tillage and crop establishment (TCE) methods in rice-wheat-greengram rotation. The treatments included: 1) random puddled transplanted rice (RPTR) - conventional-till broadcast wheat (BCW) - zero-till greengram (ZTG); 2) line PTR (LPTR) - conventional-till drill sown wheat (CTW) - ZTG; 3) machine transplanted rice in puddled soil (CTMTR) - zero tillage wheat (ZTW) - ZTG; 4) machine transplanted rice in zero-till wet soil (ZTMTR) - ZTW - ZTG; 5) system of rice intensification (SRI) - system of wheat intensification (SWI) - ZTG; 6) direct-seeded rice (DSR) - ZTW - ZTG; and 7) zero-till DSR - ZTW - ZTG. During the initial two years, conventional rice system (PTR) recorded a 16.2 % higher rice grain yield than DSR system. Whereas in the fourth year, the rice yields under DSR and PTR were comparable. As compared to SRI/SWI, the average wheat yield in ZT system was significantly high, whereas in rice, SRI/SWI system was comparable with CT system. ZTW after non-puddled rice was at par to CTW after PTR. The ZT wheat produced 4.6 % more yield than CT system. DSR production system consumed 6.8 % less water compared to transplanted system. On the system basis, 10.8 % higher net returns were recorded with CA-based system compared to conventional system. The system energy productivity under CA-based production system was 14–36 % higher than PTR-based systems. CA-based system also led to 8–10 % lower global warming potential (GWP) than conventional methods. The current study indicated that as compared to conventional system, a significant gain in productivity, profitability and energy-use efficiency, and reduction in the environmental mitigation are possible with emerging alternative TCE methods. Long-term expansion and further refinement of these technologies in local areas need to be explored for the second green revolution.
There is an urgent need for identification of the eco-friendly/cleaner production system that is more productive and profitable; efficient user of energy, water, and carbon-based inputs, and also ...environmentally safer. The four years study was conducted from 2016 to 2019, where the dominant rice-wheat cropping system is practiced extensively after ‘Green Revolution’. The objectives of the experiment were to evaluate: (1) energy budgeting, (2) carbon auditing, (3) production and economic efficiency of diverse cropping systems for upland rainfed as well as irrigated ecosystems of eastern India. Tillage and cropping system treatments were laid out according to a completely randomized block design and replicated thrice. Ten cropping sequences were comprised of: T1) a farmers’ practice of transplanted rice-wheat-mungbean, T2) conventional till-direct seeded rice (CTDSR)-wheat-mungbean, T3) soybean-maize, T4) CTDSR-mustard-urdbean, T5) foxtail millet-lentil-fallow, T6) pearl millet-chickpea-fallow, T7) finger millet-toria-fallow, T8) sorghum (grain)-chickpea-fallow, T9) maize cob–pigeon pea, and T10) sorghum (fodder)-mustard-urdbean. Energy contributions of different inputs were 42–55, 12–21, 8–18, and 4–12% for fertilizers, diesel, labour, and electricity, respectively. The amount of indirect (fertilizer, chemicals, and machinery) and direct (diesel and electricity) non-renewable energy inputs were 40–60 and 18–26%, respectively. Indirect renewable energy input (seed and crop residues) was 1–7% as compared to 15–24% of direct-renewable energy (human labour and irrigation water). The maximum energy input was recorded for T1 (53511 MJ ha−1). The maximum biomass production (40.2 Mg ha−1) was recorded with T9, while the maximum benefit: cost ratio (3.64) was noted for T10 and T8. The highest specific energy (33.5 MJ kg−1) and energy productivity (0.92 kg MJ−1) were recorded in T8 treatment. Irrespective of cropping systems, retention of crop residues accounted for 28.6–58.5% of total carbon input. The carbon sustainability index was 5–7 times higher for the millet-based production system T6 (9.32) and T8 (10.27) compared to cereal-based systems T1 (1.66) and T2 (1.21). Diversification of the rice-wheat system through climate-resilient millets-based production system reduced 84% energy consumption and 87% carbon footprint. The millet-based production system also helps in reducing the carbon input by 172% and improves the energy use efficiency by 61% compared to the cereal-based cropping system. Therefore, the study has an innovative idea to support the crop modelling, policymakers, government planners, researchers, and producers to achieve the sustainable development goals in Indo-Gangetic Plains and similar agro-climatic conditions of South Asia.
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•Carbon-cum-energy efficient production system for the diverse agro-ecosystem of South Asia.•The millet-based system reduced 84% energy use & 87% carbon-footprint than the rice-wheat system.•Energy ratio in millet-based system increase 61% output and reduction 172% carbon -input.•The millet-based had 56 & 58% more nutrient & non-renewable energy efficiency.•The millet-based emerged as a viable alternative to the rice-wheat system.
Weeds are one of the key threats in sustaining the productivity of the rice-wheat cropping system in the Indo-Gangetic Plains. The development of sound integrated weed management technologies ...requires knowledge of mechanisms that influence weed flora composition and weed seedbank dynamics. A long-term study was initiated in 2015 at Patna, Bihar, India to evaluate the effect of seven tillage and crop establishment methods on weed density, weed seedbank composition, and crop productivity in rice-wheat-mungbean rotation. All the treatments included zero-till mungbean after wheat. Tillage and crop establishment methods had differential effects on weed and weed seedbank composition. In rice, zero-till direct-seeded rice recorded 62% lower emergence of Cyperus iria, 82–90% of Echinochloa colona, and 81–83% of total weeds compared to tilled systems, but the system of rice and wheat intensification favoured E. colona. In wheat, the system of wheat intensification favoured the Phalaris minor and Solanum nigrum. Zero-till rice and wheat reduced the seedbank of Trianthema portulacastrum by 95%, and total weed seedbank by 62% compared to the system of rice and wheat intensification. Nearly, 72% of C. iria seeds, 62% of grasses, and 64% of broad-leaved weeds were in 0–15 cm soil layer. Zero-till direct-seeded rice produced a 13% lower rice grain yield than conventional puddled transplanted rice. Compared to the system of wheat intensification, zero-till wheat under triple zero-till systems produced an 11.5% higher grain yield. Managing weed seedbank is a long-term endeavour. The present study revealed that tillage and crop establishment methods influence weed density and diversity. Under zero-till rice-wheat system, rice yield decreases marginally, but the system productivity maintains due to improvement in succeeding wheat yield. This system is also helpful in reducing the weed flora density and soil weed seedbank. Regular monitoring and management of emerging pests such as armyworm (Mythimna separata) are, however, required. The study suggests that the adoption of triple zero-tillage can be a viable option for reducing the weed density and weed seedbank concurrently increasing the system productivity of the rice-wheat-mungbean cropping system in eastern Indo-Gangetic Plains.
•Effect of tillage and crop establishment on soil weed seedbank in rice-wheat-mung bean system is poorly explored.•Direct-seeded rice (DSR)-based conservation agriculture (CA) system reduced weed density and seedbank than conventional.•More than 60% weed seeds were placed in 0–15 cm soil depth.•Zero-till wheat after DSR produced higher yield than conventional till wheat after puddled transplant rice.•After five years, CA system favoured infestation of armyworm (Mythimna separata) in wheat.
Nanoclay polymer composites (NCPCs) were synthesized with partially neutralized acrylic acid and bentonites and loaded with urea and nitrification inhibitors (NIs) to act as a slow release carrier of ...nitrogen (N). The resulting product was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The XRD of NCPCs revealed that the bentonite layers were completely exfoliated and dispersed in the composite after the polymerization. The water absorbency of pure polymer (Acrylic acid + Acrylamide) was 197.53 g g
−1
and 137.75 g g
−1
by nanocomposite (8% nanobentonite) in distilled water. The nitrification inhibition ability of these NCPCs was evaluated by incubation study for 60 days in laboratory at 28°C and 50% water-holding capacity. The Schiff base -NCPCs were most effective at inhibiting nitrification (30-87%) compared to dicyandiamide and Neem oil. A column study was performed to know the movement of NH
4
-N and NO
3
-N at three different depths. Result showed that the Schiff base -NCPC decreased nitrate movement by 78.5% at the depth of 5 cm in soil column. The slow release of nitrogen and good water retention capacity confirmed that these NCPCs can be viably exploited for application in agriculture.
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