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143 results on '"Sapkota, Tek B."'

1. Enhancing productivity, soil health, and reducing global warming potential through diverse conservation agriculture cropping systems in India's Western Indo-Gangetic Plains

Author

Gora, MK, Jat, HS, Ladha, JK, Choudhary, Madhu, Sharma, PC, Yadav, AK, Singh, LK, Sapkota, Tek B, Singh, Yadvinder, Prajapat, Kailash, Yadav, RK, Jat, ML, Krupnik, TJ, and Gathala, MK

Subjects
Agriculture, Land and Farm Management, Agricultural, Veterinary and Food Sciences, Crop and Pasture Production, Climate Action, Zero Hunger, Crop diversification, Crop rotations, Greenhouse gas emissions, Indo-Gangetic Plains, Rice -wheat system, Soil quality, Soil Sciences, Agronomy & Agriculture, Agriculture, land and farm management, Crop and pasture production
Abstract

Context: The rice-wheat (RW) system, spanning 13.5 million hectares in South Asia, is crucial for food security and livelihoods. However, intensive conventional tillage-based practices have harmed soil and environmental health, decreased productivity trends and increased greenhouse gas emissions. Objective: This study aims to develop resilient, climate-smart cropping systems within the RW system, focusing on soil and crop productivity, economic viability, and reduced greenhouse gas (GHG) emissions. Methods: Over eight years, the study evaluated diverse parameters compared to farmer practices (FP) in seven scenarios (Sc), including one representing FP (Sc1) and six based on conservation agriculture (CA) principles. The study assessed system crop productivity, economic returns, soil quality (organic carbon; OC, nitrogen; N, phosphorus; P, potassium; K contents, bulk density; BD, soil aggregation, infiltration rates, microbial counts, and earthworm density), and GHG emissions. Results: CA-based scenarios (Sc2 to Sc7) showed improved soil quality, lower bulk density, enhanced soil aggregation, and increased infiltration rates compared to Sc1. In the 0–15 cm layer, surface soil organic carbon (OC) and C stock were 63.7 % and 49.6 % higher, respectively, in CA-based scenarios. Additionally, available N, P and K contents in the surface layer increased by 10.2 %, 28.6 %, and 21.8 % under CA-based scenarios. Adoption of CA in intensified maize-based scenarios (Sc4 and Sc5) led to the increased system and economic yields, higher soil quality index (SQI), reduced GHG emissions and increased C stock compared to Sc1. Implications: The study highlights that Conservation Agriculture (CA) practices and diversified crop rotations can address issues like falling crop productivity, reduced economic returns, soil degradation, and increasing environmental impacts in northwestern India's traditional rice-wheat system. However, widespread adoption requires government policies, including C credit payments and guaranteed markets with supportive pricing.

Published
2024

3. Overcoming barriers to climate-smart agriculture in South Asia

Author

Ishtiaque, Asif, Krupnik, Timothy J., Krishna, Vijesh, Uddin, Md. Nasir, Aryal, Jeetendra Prakash, Srivastava, Amit Kumar, Kumar, Shalander, Shahzad, Muhammad Faisal, Bhatt, Rajan, Gardezi, Maaz, Bahinipati, Chandra Sekhar, Nazu, Shahnaz Begum, Ghimire, Rajiv, Anik, Asif Reza, Sapkota, Tek B., Ghosh, Madhusudan, Subedi, Roshan, Sardar, Asif, Uddin, K. M. Zasim, Khatri-Chhetri, Arun, Rahman, Md. Shahinoor, Balwinder-Singh, and Jain, Meha

Published
2024
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5. Pathways and determinants of sustainable energy use for rice farms in India

Author

Nayak, Hari Sankar, Parihar, Chiter Mal, Aravindakshan, Sreejith, Silva, ‪João Vasco, Krupnik, Timothy J., McDonald, Andrew J., Kakraliya, Suresh K., Sena, Dipaka R., Kumar, Virender, Sherpa, Sonam R., Bijarniya, Deepak, Singh, Love K., Kumar, M., Choudhary, Kajod M., Kumar, S., Kumar, Y., Jat, Hanuman S., Sidhu, Harminder S., Jat, Mangi L., and Sapkota, Tek B.

Published
2023
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7. Changes in soil biology under conservation agriculture based sustainable intensification of cereal systems in Indo-Gangetic Plains

Author

Choudhary, Madhu, Datta, Ashim, Jat, Hanuman S, Yadav, Arvind K, Gathala, Mahesh K, Sapkota, Tek B, Das, Amit K, Sharma, Parbodh C, Jat, Mangi L, Singh, Rajbir, and Ladha, Jagdish K

Subjects
Zero Hunger, Cropping system, Microbial biomass carbon, Microbial biomass nitrogen, Soil micro-arthropods, Soil quality index, Tillage, Environmental Sciences, Biological Sciences, Agricultural and Veterinary Sciences, Agronomy & Agriculture
Abstract

Continuous rice-wheat (RW) rotation with conventional agronomic practices has resulted in declining factor productivity and degrading soil resources. A farmer's participatory research trial was conducted in Karnal, India to evaluate 8 combinations of cropping systems, tillage, crop establishment method and residue management effects on key soil physico-chemical and biological properties. Treatments (T) 1–4 involved RW and 5–8 maize-wheat (MW) with conventional tillage (CT) and zero tillage (ZT) with (+ R) and without (− R) residue recycling. Residue was either incorporated (Ri) or mulched (Rm). Treatment 1 (RW/CT − R) had the highest bulk density (BD) (1.47 Mg m−3) and T8 (MW/ZT + Rm), the lowest (1.34 Mg m−3). After 3 years of cropping, soil accumulated more organic C in (a) MW (9.33 Mg ha−1) than RW (8.5 Mg ha−1), (b) ZT (9.25 Mg ha−1) than CT (8.58 Mg ha−1), and (c) + R (10.18 Mg ha−1) than –R (7.65 Mg ha−1). MW system with ZT and residue (T8: MW/ZT + Rm) registered 208, 263, 210 and 48% improvement in soil microbial biomass C (MBC) and N, dehydrogenase activity (DHA) and alkaline phosphatase activity (APA), whereas RW system in T4 (RW/ZT + Rm) registered 83, 81, 44 and 13%, respectively as compared with T1 (RW/CT − R), the business as usual scenario. Treatment 8 (MW/ZT + Rm) recorded the highest microbial population viz. bacteria, fungi and actinomycetes. The most abundant micro-arthropods present in the soil of experimental plot were Collembola, Acari and Protura which varied with treatments. Soil MBC, APA, BD and micro-arthropod population were identified as the key indicators and contributed significantly towards soil quality index (SQI). MW system with ZT and Rm (T8) recorded the highest SQI (1.45) followed by T6 (1.34) and the lowest score (0.29) being in T1 (RW/CT − R). The SQI was higher by 90% in MW compared to RW, 22% in ZT compared to CT, and 100% in residue recycling compared with residue removal. System yield was strongly related to key soil quality indicators and also positively correlated with SQI. Longer-term studies are essential to realize maximal effects of improvements in soil health on crop yields.

Published
2018

20. Interpretable machine learning methods to explain on-farm yield variability of high productivity wheat in Northwest India

Author

Nayak, Hari Sankar, primary, Silva, João Vasco, additional, Parihar, Chiter Mal, additional, Krupnik, Timothy J., additional, Sena, Dipaka Ranjan, additional, Kakraliya, Suresh K., additional, Jat, Hanuman Sahay, additional, Sidhu, Harminder Singh, additional, Sharma, Parbodh C., additional, Jat, Mangi Lal, additional, and Sapkota, Tek B., additional

Published
2022
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23. Adapted Conservation Agriculture Practices Can Increase Energy Productivity and Lower Yield-Scaled Greenhouse Gas Emissions in Coastal Bangladesh

Author

Krupnik, Timothy J., Hossain, Md. Khaled, Timsina, Jagadish, Gathala, Mahesh K., Sapkota, Tek B., Yasmin, Samina, Shahjahan, Md., Hossain, Farhad, Kurishi, Alanuzzaman, Miah, Azahar Ali, Rahman, B. M. Saidur, and McDonald, Andrew J.

Subjects
Soil Science, Plant Science, Agricultural and Biological Sciences (miscellaneous), Agronomy and Crop Science
Abstract

While numerous studies have documented the benefits of conservation agriculture (CA) in South Asia, most focus on favorable environments where farmers have reliable access to energy supporting irrigation and inputs. The performance of CA in South Asia’s under-developed coastal environments is comparatively understudied. In these environments, farmers are increasingly interested in growing a second crop to meet food security and income generation objectives in rotation following the predominant monsoon season rice crop, though labor, energy costs, and investment constraints limit their ability to do so. We hypothesized that rotating rice (Oryza sativa) with maize (Zea mays) using conservation agriculture, or CA (i.e., strip-tilled maize followed by unpuddled transplanted rice), or seasonally alternating tillage (SAT, i.e., strip-tilled maize followed by fully-tilled, puddled rice with residues retained across rotations) would reduce costs and energy use, increase energy-use efficiency, and reduce yield-scaled CO2-eq emissions (YSE) and total global warming potential (GWP), compared to farmers’ own practices (FP) and conventional full-tillage (CT) under the same rotation in Bangladesh’s coastal region. Starting with winter maize followed by summer rice, we evaluated four tillage and crop establishment treatments in farmer-managed experiments in partially irrigated and rainfed environments over three years in 35 farmer’s fields across Bangladesh’s coastal districts. Treatments included FP, CT, complete CA, and SAT under a rice-maize rotation. Across years, the full suite of CA practices and SAT were significantly more energy-efficient and energy-productive than FP or CT. The order of YSE in rice was CA< CT or FP < SAT while in maize, it was CA or SAT < FP < CT. Across environments, CA and SAT resulted in 15-18% higher yield at the cropping systems level (maize and rice yields combined) and 26-40% less manual labor than CT or FP. CA and SAT also reduced by 1-12% and 33-35% total production costs respective to CT and FP. This was associated with 13-17% greater grain energy output in CA and SAT, and 2-18% lower YSE, compared to CT or FP. While our data suggest that both CA and SAT can result in a range of positive agronomic, economic, and environmental outcomes compared to FP or CT, post-trial surveys and discussions with farmers revealed a strong practical aversion to use of the full suite of CA practices and preference for adapted practices due to logistical constraints in negotiating the hire of laborers for unpuddled manual transplanting.

Published
2022

24. The optimization of conservation agriculture practices requires attention to location-specific performance: Evidence from large scale gridded simulations across South Asia

Author

Zhang, Tianning, primary, Xiong, Wei, additional, Sapkota, Tek B., additional, Jat, M.L., additional, Montes, Carlo, additional, Krupnik, Timothy J., additional, Jat, Raj Kumar, additional, Karki, Saral, additional, Nayak, Harisankar, additional, Faisal, Asif Al, additional, and Jat, H.S., additional

Published
2022
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27. Rice yield gaps and nitrogen-use efficiency in the Northwestern Indo-Gangetic Plains of India: Evidence based insights from heterogeneous farmers’ practices

Author

Nayak, Hari Sankar, primary, Silva, João Vasco, additional, Parihar, Chiter Mal, additional, Kakraliya, Suresh K., additional, Krupnik, Timothy J., additional, Bijarniya, Deepak, additional, Jat, Mangi Lal, additional, Sharma, Parbodh C., additional, Jat, Hanuman Sahay, additional, Sidhu, Harminder Singh, additional, and Sapkota, Tek B., additional

Published
2022
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31. Quantifying opportunities for greenhouse gas emissions mitigation using big data from smallholder crop and livestock farmers across Bangladesh

Author

Sapkota, Tek B., primary, Khanam, Fahmida, additional, Mathivanan, Gokul Prasad, additional, Vetter, Sylvia, additional, Hussain, Sk. Ghulam, additional, Pilat, Anne-Laure, additional, Shahrin, Sumona, additional, Hossain, Md. Khaled, additional, Sarker, Nathu Ram, additional, and Krupnik, Timothy J., additional

Published
2021
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34. Spatially explicit database on crop-livestock management, soil, climate, greenhouse gas emissions and mitigation potential for all of Bangladesh

Author

Sapkota, Tek B., primary, Khanam, Fahmida, additional, Mathivanan, Gokul Prasad, additional, Vetter, Sylvia, additional, Hussain, Sk. Ghulam, additional, Pilat, Anne-Laure, additional, Shahrin, Sumona, additional, Hossain, Md. Khaled, additional, Sarker, Nathu Ram, additional, and Krupnik, Timothy J., additional

Published
2021
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35. Improving nitrogen use efficiency and reducing nitrogen surplus through best fertilizer nitrogen management in cereal production: The case of India and China

Author

Sapkota, Tek B., Bijay-Singh, and Takele, Robel

Abstract

China and India are the two top consumers of fertilizer nitrogen (N) in the world not only to provide food security to 36% of the global population living in the two countries but also due to fertilizer-related government policies being followed during the last more than 50 years. Excessive fertilizer N use is now a cause of N-related environmental pollution as well as a concern for climate change. Nitrogen use efficiency (NUE) at farmers' fields dictates both production of food crops as well as loss of N to the environment including efforts to curb climate change due to N2O emission. We used a gridded database on N input and N output for wheat, rice, and maize in China and India from 1961 to 2013 to synthesize the dynamics of NUE (percentage of applied N used by the crop) and surplus N (difference between total N input and N output) and in the light of relevant literature interpreted it in terms of past and future fertilizer N management scenarios and fertilizer related policies in the two countries. From 1961 to 2013, the percentage of fertilizer N in total N input in cereal crop production increased from 8–10% to 71–75% in India and from 30–37% to 80–84% in China. In both India and China, NUE has been continuously declining and in 2013 it was in the range of 20–24% (except 32% for wheat in India) due to several-fold increases in fertilizer N use and imbalanced use of fertilizer nutrients (particularly in India)—a consequence of huge subsidies provided by the governments on different fertilizer products. Estimates of maximum N output in the form of crop yield at saturating N input regimes determined from trajectories of N output as a function of total N input for 1961–2013 and 2001–13 revealed that crop and fertilizer N management for rice, wheat, and maize in India and China did not improve significantly since the Green Revolution era. As a large number of studies in India and China show that NUE can be increased by the advancement of technology front in terms of crop and fertilizer management and by reducing the fertilizer N rate without a significant reduction in the yield of crops, recommendations have been given for governments (to frame suitable policies), farmers, extension agencies, and fertilizer dealers.

Published
2023
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44. Corrigendum to “Greenhouse gas emissions from agricultural food production to supply Indian diets: Implications for climate change mitigation” [Agric. Ecosyst. Environ. 237 (2017) 234–241]

Author

Vetter, Sylvia H., primary, Sapkota, Tek B., additional, Hillier, Jon, additional, Stirling, Clare M., additional, Macdiarmid, Jennie I., additional, Aleksandrowicz, Lukasz, additional, Green, Rosemary, additional, Joy, Edward J.M., additional, Dangour, Alan D., additional, and Smith, Pete, additional

Published
2019
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46. Re-assessing nitrous oxide emissions from croplands across Mainland China

Author

Yue, Qian, primary, Ledo, Alicia, additional, Cheng, Kun, additional, Albanito, Fabrizio, additional, Lebender, Ulrike, additional, Sapkota, Tek B., additional, Brentrup, Frank, additional, Stirling, Clare M., additional, Smith, Pete, additional, Sun, Jianfei, additional, Pan, Genxing, additional, and Hillier, Jonathan, additional

Published
2018
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47. Long-term impact of conservation agriculture and diversified maize rotations on carbon pools and stocks, mineral nitrogen fractions and nitrous oxide fluxes in inceptisol of India

Author

Parihar, C.M., primary, Parihar, M.D., additional, Sapkota, Tek B., additional, Nanwal, R.K., additional, Singh, A.K., additional, Jat, S.L., additional, Nayak, H.S., additional, Mahala, D.M., additional, Singh, L.K., additional, Kakraliya, S.K., additional, Stirling, Clare M., additional, and Jat, M.L., additional

Published
2018
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48. Greenhouse gas emissions from agricultural food production to supply Indian diets: Implications for climate change mitigation

Author

Vetter, Sylvia H., Sapkota, Tek B., Hillier, Jon, Stirling, Clare M., Macdiarmid, Jennie I., Aleksandrowicz, Lukasz, Green, Rosemary, Joy, Edward J.M., Dangour, Alan D., and Smith, Pete

Subjects
Ecology, Animal Science and Zoology, Agronomy and Crop Science
Abstract

Agriculture is a major source of greenhouse gas (GHG) emissions globally. The growing global population is putting pressure on agricultural production systems that aim to secure food production while minimising GHG emissions. In this study, the GHG emissions associated with the production of major food commodities in India are calculated using the Cool Farm Tool. GHG emissions, based on farm management for major crops (including cereals like wheat and rice, pulses, potatoes, fruits and vegetables) and livestock-based products (milk, eggs, chicken and mutton meat), are quantified and compared. Livestock and rice production were found to be the main sources of GHG emissions in Indian agriculture with a country average of 5.65 kg CO2eq kg−1 rice, 45.54 kg CO2eq kg−1 mutton meat and 2.4 kg CO2eq kg−1 milk. Production of cereals (except rice), fruits and vegetables in India emits comparatively less GHGs with

Published
2017

49. Climate change and agriculture in South Asia: adaptation options in smallholder production systems.

Author

Aryal, Jeetendra Prakash, Sapkota, Tek B., Khurana, Ritika, Khatri-Chhetri, Arun, Rahut, Dil Bahadur, and Jat, M. L.

Subjects
CLIMATE change, AGRICULTURAL climatology, AGRICULTURAL technology, AGRICULTURAL productivity, CLIMATE change research
Abstract

Agriculture in South Asia is vulnerable to climate change. Therefore, adaptation measures are required to sustain agricultural productivity, to reduce vulnerability, and to enhance the resilience of the agricultural system to climate change. There are many adaptation practices in the production systems that have been proposed and tested for minimizing the effects of climate change. Some socioeconomic and political setup contributes to adaptation, while others may inhibit it. This paper presents a systematic review of the impacts of climate change on crop production and also the major options in the agricultural sector that are available for adaptation to climate change. One of the key conclusions is that agricultural practices that help climate change adaptation in agriculture are available, while the institutional setup to implement and disseminate those technical solutions is yet to be strengthened. Thus, it is important to examine how to bring the required institutional change, generate fund to invest on these changes, and design dynamic policies for long-term climate change adaptation in agriculture rather than a mere focus on agricultural technology. This is one of the areas where South Asian climate policies require reconsidering to avoid possible maladaptation in the long run. [ABSTRACT FROM AUTHOR]

Published
2020
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