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1.
Nat Commun ; 15(1): 8403, 2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39333483

RESUMO

Yield gap analysis is used to characterize the untapped production potential of cropping systems. With emerging large-n agronomic datasets and data science methods, pathways for narrowing yield gaps can be identified that provide actionable insights into where and how cropping systems can be sustainably intensified. Here we characterize the contributing factors to rice yield gaps across seven Indian states, with a case study region used to assess the power of intervention targeting. Primary yield constraints in the case study region were nitrogen and irrigation, but scenario analysis suggests modest average yield gains with universal adoption of higher nitrogen rates. When nitrogen limited fields are targeted for practice change (47% of the sample), yield gains are predicted to double. When nitrogen and irrigation co-limitations are targeted (20% of the sample), yield gains more than tripled. Results suggest that analytics-led strategies for crop intensification can generate transformative advances in productivity, profitability, and environmental outcomes.


Assuntos
Irrigação Agrícola , Agricultura , Produção Agrícola , Produtos Agrícolas , Oryza , Oryza/crescimento & desenvolvimento , Índia , Produtos Agrícolas/crescimento & desenvolvimento , Produção Agrícola/métodos , Irrigação Agrícola/métodos , Agricultura/métodos , Nitrogênio/metabolismo , Fertilizantes
2.
Field Crops Res ; 302: 109078, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37840837

RESUMO

Context or problem: In the Indian state of Odisha, rice-based system productivity is poor due to: (i) low rice yield in the monsoon (wet) season (2-4 t ha-1 compared to 6-8 t ha-1 in Punjab or Haryana); and (ii) limited cropping during the post-monsoon (dry) season (59% of the wet season rice area is left fallow in the dry season). Objective: Our study identifies strategies for increasing rice-based system productivity through: (i) alternative crop establishment methods in the wet season (Dry-Direct Seeded Rice or DSR, and mechanical puddled transplanted rice or PTR-M) to traditional methods such as broadcasting followed by post-emergence tillage (locally known as beushening) and manual random puddled transplanted rice (PTR-R); (ii) to identify rice-fallow areas suitable for pulse and oilseed cultivation in the dry season; and (iii) to evaluate the performance of short-duration pulses (green gram, Vigna radiata; black gram, Vigna mungo), and oilseeds (Brassica rapa var. toria, Helianthus annuus) in rice-fallow areas in the dry season. Methods: On-farm experiments were conducted between 2017 and 2019 in three districts of Odisha (Bhadrak, Cuttack and Mayurbhanj) to evaluate DSR compared to beushening and PTR-R; and PTR-M compared to PTR-R and manual line puddled transplanted rice (PTR-L) in the wet season. The data from Landsat-8 Operational Land Imager (OLI) and Sentinel-1satellite sensors was used to identify rice-fallow areas, and the daily SMAP (Soil Moisture Active Passive) L-band soil moisture was used for mapping suitable rice-fallow areas for growing pulses and oilseeds. Short duration crops were evaluated in suitable rice-fallow areas. Results: In the wet season, DSR (range -4 to + 53%) had a significant effect on rice yield over beushening. Similarly, PTR-M consistently increased rice yield by 16-26% over PTR-R, and by 5-23% over PTR-L. In the dry season, pulse crops (green gram and black gram) performed well compared to Indian mustard under rainfed cultivation. However, under irrigated conditions, dry-season rice yield was more productive than the rice equivalent yield of green gram, black gram and sunflower. We found that 1.03 M ha (i.e., ∼50%) of total rice-fallow areas of 2.1 M ha were suitable for growing short duration green gram and black gram in the dry season. Conclusions: We conclude that system productivity and cropping intensity can be increased by adoption of DSR and PTR-M in the wet season, and growing of green gram and black gram in the dry season. Implications: Odisha state can potentially produce an additional 0.67 million tonnes pulses if suitable rice-fallow areas are brought under green gram and black gram cultivation in the dry the season.

3.
Agric Water Manag ; 283: 108287, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37265577

RESUMO

Climate variability and insufficient irrigation are primary constraints to stable and higher agricultural productivity and food security in Nepal. Agriculture is the largest global freshwater user, and integration of surface- and ground-water use is frequently presented as an strategy for increasing efficiency as well as climate change adaptation. However, conjunctive management (CM) planning often ignores demand-side requirements and a broader set of sustainable development considerations, including ecosystem health and economics of different development strategies. While there is generic understanding of conjunctive use, detailed technical knowhow to realize the CM is lacking in Nepal. This article presents a holistic framework through literature reviews, stakeholders consultations and expert interviews for assessing CM and implementation prospects from a systems-level perspective. We demonstrate the framework through a case study in Western Nepal, where climatic variability and a lack of irrigation are key impediments to increased agricultural productivity and sustainable development. Results show that knowledge of water resources availability is good and that of water demand low in the Western Terai. Additional and coordinated investments are required to improve knowledge gaps as well as access to irrigation. There is therefore a need to assess water resources availability, water access, use and productivity, to fill the knowledge gaps in order to pave pathways for CM. This paper also discusses some strategies to translate prospects of conjunctive management into implementation.

4.
Agric Syst ; 207: 103618, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37091836

RESUMO

CONTEXT: Millions of people living in the Eastern Gangetic Plains (EGP) of India engage in agriculture to support their livelihoods yet are income poor, and food and climate insecure. To address these challenges, policymakers and development programs invest in irrigation-led agricultural intensification. However, the evidence for agricultural intensification to lift farmers' incomes above the poverty line remains largely anecdotal. OBJECTIVE: The main objective of this study is to use a large household survey (n = 15,572; rice: 8244, wheat: 7328; 2017/18) to assess the link between agricultural intensification and personal daily incomes from farming (FPDI) in the rice-wheat systems of the EGP - the dominant cropping system of the region. METHODS: We use the Intensification Benefit Index (IBI), a measure that relates farm size and household size to FPDI, to assess how daily incomes from rice-wheat production change with irrigation-led intensification across the EGP. RESULTS AND CONCLUSIONS: Relative to the international poverty line of 1.90 Purchasing Power Parity (PPP)$ day-1 and accounting for variations in HH size in the analysis, we found that small farm sizes limit the potential for agricultural intensification from irrigation to transform the poverty status of households in the bottom three quartiles of the IBI. The estimated median FPDI of households with intensified systems in the bottom three quartiles is only 0.51 PPP$ day-1 (a 0.15 PPP$ gain). The median FPDI increases to 2.10 PPP$ day-1 for households in the upper quartile of the IBI distribution (a 0.30 PPP$ gain). Irrigation-led agricultural intensification of rice-wheat systems in the EGP may provide substantial benefits for resilience to climatic change and food security but achieving meaningful poverty reduction will require complementary investments. SIGNIFICANCE: Transforming the poverty status of most smallholder farmers in the EGP requires diversified portfolios of rural on- and off-farm income-generating opportunities. While bolstering food- and climate security, agronomic intervention programs should consider smallholders' limited monetary incentives to invest in intensification. Irrigation-led agricultural intensification programs and policies should explicitly account for the heterogeneity in household resources, irrigation levels, and degree of dependence on agricultural income.

5.
Nat Food ; 3(7): 542-551, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-37117949

RESUMO

India will need to produce 30% more wheat by 2050, and these gains must principally come from intensification in eastern India where low productivity is common. Through a dense network of on-farm surveys for the rice-wheat system in this region, we show that contemporary wheat sowing dates have a central influence on achieved and attainable yields, superseding all other crop management, soil and varietal factors. We estimate that untapped wheat production potential will increase by 69% with achievable adjustments to wheat sowing dates without incurring undesirable trade-offs with rice productivity, irrigation requirements or profitability. Our findings also indicate that transformative gains in wheat yields are only possible in eastern India if rice and wheat are managed as a coupled system. Steps taken to 'keep time' through better management of the annual cropping calendar will pay dividends for food security, profitability and climate resilience now and as a foundation for adaptation to progressive climate change.

6.
Sci Rep ; 11(1): 15901, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34354160

RESUMO

Climate-smart agriculture (CSA)-based management practices are getting popular across South-Asia as an alternative to the conventional system for particular weed suppression, resources conservation and environmental quality. An 8-year study (2012-2013 to 2019-2020) was conducted to understand the shift in weed density and diversity under different CSA-based management practices called scenarios (Sc). These Sc involved: Sc1, conventional tillage (CT)-based rice-wheat system with flood irrigation (farmers' practice); Sc2, CT-rice, zero tillage (ZT)-wheat-mungbean with flood irrigation (partial CA-based); Sc3, ZT rice-wheat-mungbean with flood irrigation (partial CSA-based rice); Sc4, ZT maize-wheat-mungbean with flood irrigation (partial CSA-based maize); Sc5, ZT rice-wheat-mungbean with subsurface drip irrigation (full CSA-based rice); and Sc6, ZT maize-wheat-mungbean with subsurface drip irrigation (full CSA-based maize). The most abundant weed species were P. minor > A. arvensis > M. indicus > C. album and were favored by farmers' practice. However, CSA-based management practices suppressed these species and favored S. nigrum and R. dentatus and the effect of CSAPs was more evident in the long-term. Maximum total weed density was observed for Sc1, while minimum value was recorded under full CSA-based maize systems, where seven weed-species vanished, and P. minor density declined to 0.33 instead of 25.93 plant m-2 after 8-years of continuous cultivation. Full CSA-based maize-wheat system could be a promising alternative for the conveniently managed rice-wheat system in weed suppression in north-west India.

7.
Agron Sustain Dev ; 41(2): 14, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33680098

RESUMO

Timely crop planting is a foundation for climate-resilient rice-wheat systems of the Eastern Gangetic Plains-a global food insecurity and poverty hotspot. We hypothesize that the capacity of individual farmers to plant on time varies considerably, shaped by multifaceted enabling factors and constraints that are poorly understood. To address this knowledge gap, two complementary datasets were used to characterize drivers and decision processes that govern the timing of rice planting in this region. The first dataset was a large agricultural management survey (rice-wheat: n = 15,245; of which rice: n = 7597) from a broad geographic region that was analyzed by machine learning methods. The second dataset was a discussion-based survey (n = 112) from a more limited geography that we analyzed with graph theory tools to elicit nuanced information on planting decisions. By combining insights from these methods, we show for the first time that differences in rice planting times are primarily shaped by ecosystem and climate factors while social factors play a prominent secondary role. Monsoon onset, surface and groundwater availability, and land type determine village-scale mean planting times whereas, for resource-constrained farmers who tend to plant later ceteris paribus, planting is further influenced by access to farm machinery, seed, fertilizer, and labor. Also, a critical threshold for economically efficient pumping appears at a groundwater depth of around 4.5 m; below this depth, farmers do not irrigate and delay planting. Without collective action to spread risk through synchronous timely planting, ecosystem factors such as threats posed by pests and wild animals may further deter early planting by individual farmers. Accordingly, we propose a three-pronged strategy that combines targeted strengthening of agricultural input chains, agroadvisory development, and coordinated rice planting and wildlife conservation to support climate-resilient agricultural development in the Eastern Gangetic Plains.

8.
Sci Rep ; 10(1): 19267, 2020 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-33159103

RESUMO

In the western Indo-Gangetic plains, issues of deterioration in soil, water, and environment quality coupled with low profitability jeopardize the sustainability of the dominant rice-wheat (RW) system. To address these issues, crop diversification and conservation agriculture (CA)-based management hold considerable promise but the adoption of both approaches has been low, and additional evidence generation from a multi-criteria productivity and sustainability perspective is likely required to help drive the change. Compared to prevailing farmers' practice (FP), results suggest that CA-based rice management increased profitability by 13% and energy use efficiency (EUE) by 21% while reducing irrigation by 19% and global warming potential (GWP) by 28%. By substituting CA-based maize for rice, similar mean profitability gains were realized (16%) but transformative improvements in irrigation (- 84%), EUE (+ 231%), and GWP (- 95%) were observed compared to FP. Inclusion of mungbean in the rotation (i.e. maize-wheat-mungbean) with CA-based management increased the system productivity, profitability, and EUE by 11, 25 and 103%, respectively while decreasing irrigation water use by 64% and GWP by 106% compared to FP. Despite considerable benefits from the CA-based maize-wheat system, adoption of maize is not widespread due to uneven market demand and assured price guarantees for rice.

9.
Food Secur ; 12(4): 761-768, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32837652

RESUMO

In the context of developing countries, early evidence suggests that the impacts of the COVID-19 pandemic on food production systems is complex, heterogenous, and dynamic. As such, robust monitoring of the impact of the health crisis and containment measures across agricultural value chains will likely prove vitally important. With Bangladesh as a case study, we discuss the building blocks of a comprehensive monitoring system for prioritizing and designing interventions that respond to food system disruptions from COVID-19 and preemptively avoid further cascading negative effects. We also highlight the need for parallel research that identifies pathways for enhancing information flow, analysis, and action to improve the efficiency and reliability of input and output value chains. In aggregate, this preliminary work highlights the building blocks of resilient food systems to external shocks such as COVID-19 pandemic in the context of developing nations. In doing so, we call attention to the importance of 'infection safe' agricultural input and output distribution logistics, extended social safety nets, adequate credit facilities, and innovative labor management tools alongside, appropriate farm mechanization. In addition, digital extension services, circular nutrient flows, enhanced storage facilities, as well as innovative and robust marketing mechanisms are required. These should be considered in parallel with effective international trade management policies and institutions as crucial supportive measures.

10.
Field Crops Res ; 250: 107776, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32362715

RESUMO

Conventionally managed rice-wheat systems of the eastern Indo-Gangetic Plains (E-IGP) that rely on soil puddling for rice and intensive tillage for wheat are low-yielding and resource-inefficient, leading to low profitability. While a host of alternative tillage and crop establishment (TCE) methods have been advocated as solutions for sustainably enhancing productivity and profitability, few systematic comparisons of these methods are reported. To address this gap, a three-year field study was conducted in Bihar, India with the goal of identifying TCE methods for rice-wheat systems that are high yielding, less resource-intensive, and more profitable. The following systems were evaluated: 1) puddled transplanted rice (PTR) followed by (fb) conventional tillage wheat (CTW) or zero-tillage wheat (ZTW); 2) machine transplanted rice in non-puddled soil (MTR) fb ZTW; 3) the system of rice intensification (SRI) fb system of wheat intensification (SWI); and 4) dry-seeded rice (DSR) fb ZTW. Rice cultivar duration (short versus medium-duration) was incorporated as a subplot treatment in all systems. Rice yields were similar with all methods, except DSR yield was 11 % lower and MTR yield was 7% higher than PTR in the third year. Cost of production was US$ 149 and 77 ha-1 lower in DSR and MTR, respectively, and US$ 84 ha-1 higher in SRI than PTR. The gross margin and benefit-cost (B:C) ratio was highest in MTR followed by DSR and lowest in SRI. In wheat, ZT resulted in a higher yield than CTW, especially when ZTW was cultivated after non-puddled rice (e.g., DSR or MTR). ZTW reduced production costs by US$ 69 ha-1, whereas SWI increased it by US$ 139 ha-1 relative to CTW. The higher yield and lower cost of production resulted in a higher gross margin (US$ 82-355 ha-1 and US$ 129-409 ha-1 higher than CTW and SWI, respectively) and a higher B:C ratio in ZTW treatments than CTW and SWI. At the system level, MTR or DSR followed by ZTW had both superior crop yields and consistently higher gross margins (US $133 to 382 ha-1) than other practices. On the other hand, the SRI fb SWI system had no yield advantage and poorer economic performance than conventional practices. In all systems, the inclusion of a medium-duration rice hybrid resulted in higher rice and system yields. These results suggest that significant gains in profitability are possible with emerging TCE practices in rice-wheat systems, but alternatives such as the SRI and SWI will likely erode farmer incomes.

11.
PLoS One ; 15(4): e0231377, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32298316

RESUMO

Lentil (Lens culinaris Medik.) is a cool-season pulse grown in winter cropping cycle in South Asia and provides a major source of nutrition for many low-income households. Lentil productivity is perceived to be sensitive to high rainfall, but few studies document spatial and temporal patterns of yield variation across climate, soil, and agronomic gradients. Using farm survey data from Nepal, this study characterizes patterns of lentil productivity and efficiency for two cropping seasons. Additional insights were derived from on-farm trials conducted over a 5-year period that assess agronomic, drainage, and cultivar interventions. To contextualize the inferences derived from farm surveys and trials, the Stempedia model was used to simulate the severity of Stemphylium blight (Stemphylium botryosum) risk-the principal fungal disease in lentil-with 30 years of historical climate data. Although development efforts in Nepal have prioritized pulse intensification, results confirm that lentil remains a risky enterprise highlighting the prevalence of crop failures (16%), modest yields (353 kg ha-1), and low levels of profitability (US$ 33 ha-1) in wet winters. Nevertheless, site factors such as drainage class influence responses with upland sites performing well in wet winters and lowland sites performing well in dry winters. In wet winters, a phenomena perceived to be increasing, 76% of surveyed farmers reported significant disease pressure and simulations with Stempedia predict that conditions favoring Stemphylium occur in >60% of all years. Nevertheless, simulation results also suggest that these risks can be addressed through earlier planting. Based on the combined results, gains in yield, yield stability, and technical efficiency can be enhanced in western Nepal by: 1) ensuring timely lentil planting to mitigate climate-mediated disease risk, 2) evaluating new lentil lines that may provide enhanced resistance to diseases and waterlogging, and 3) encouraging the emergence of mechanization solutions to overcome labor bottlenecks.


Assuntos
Biomassa , Clima , Produção Agrícola/métodos , Produtos Agrícolas/crescimento & desenvolvimento , Lens (Planta)/crescimento & desenvolvimento , Simulação por Computador , Produção Agrícola/normas , Nepal
12.
Water Int ; 45(1): 39-59, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32256943

RESUMO

Most rice farmers in Nepal's Terai region do not fully utilize irrigation during breaks in monsoon rainfall. This leads to yield losses despite abundant groundwater resources and ongoing expansion of diesel pumps and tubewell infrastructure. We investigate this puzzle by characterizing delay factors governing tubewell irrigation across wealth and precipitation gradients. After the decision to irrigate, different factors delay irrigation by roughly one week. While more sustainable and inexpensive energy for pumping may eventually catalyze transformative change, we identify near-term interventions that may increase rice farmers' resilience to water stress in smallholder-dominated farming communities based on prevailing types of irrigation infrastructure.

13.
J Agric Econ ; 71(1): 199-218, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32025043

RESUMO

The 'high speed' rotavator is used for shallow tillage to create a fine tilth and incorporate crop residues, often with a single tractor pass. Rotavator tillage has spread quickly in many parts of South Asia, despite short-term experimental trials suggesting deteriorating soil quality and crop yield penalties. Evidence of rotavator impacts on farmer fields across soil gradients and time is largely absent. From a farm household survey conducted among wheat farmers in Nepal, we estimate wheat yield and profitability outcomes for rotavator adopters and non-adopters using propensity score matching. We find that rotavator adoption leads to inferior outcomes, despite significant cost savings for land preparation (US$ 11-15 per hectare). With rotavator adoption, farmers lose about 284-309 kg of wheat grain and about US$ 93-101 of profits on average per hectare per season, and these penalties increase with longer-term use of the technology. Adoption of rotavator appears to be driven by the cost and time savings for land preparation. Against this backdrop, new policy and extension efforts are required that discourage rotavator use and favour more sustainable tillage technologies.

14.
Field Crops Res ; 259: 107961, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34149151

RESUMO

In many parts of Eastern India that have a very high prevalence of rural poverty and food insecurity, the prevailing rice establishment practice of 'beushening' is characterized by low yields and modest profitability, while labor and energy inputs are high. Beushening consists of broadcasting ungerminated rice seed at high rates (>100 kg ha-1) prior to the onset of monsoon rain, followed by ploughing at 4-6 weeks after crop emergence to control weeds with subsequent manual gap filling through seedling redistribution to ensure stand uniformity. Dry-direct seeding of rice (DSR), both drill-DSR and precision broadcast-DSR in combination with integrated weed management (IWM) may offer a pathway for simultaneously reducing costs and markedly increasing productivity. On-farm trials were conducted from 2016 to 2018 in four districts of Odisha (Mayurbhanj, Cuttack, Bhadrak, and Puri) to evaluate the yield and economic performance of dry-DSR (drill and precision broadcast), coupled with herbicide-based IWM strategies, in comparison with conventional beushening. Drill-DSR with IWM increased grain yield by 1.7 t ha-1 in Mayurbhanj and 1.3 t ha-1 in Cuttack, but not in Bhadrak, compared to beushening. The combination of increased yield and lower variable cost in drill-DSR increased net benefit by 550, 395, and 166 US$ ha-1 in Mayurbhanj, Cuttack, and Bhadrak, respectively. For farmers without access to seed drills, precision broadcast-DSR with IWM increased yields by 0.91, 1.22 and 0.60 t ha-1, and net benefits by 270, 312, and 188 US$ ha-1 in Mayurbhanj, Puri, and Bhadrak, respectively. Among the IWM practices evaluated in dry-DSR, application of pretilachlor + safener @ 500 g ai ha-1 as pre-emergence, followed by bispyribac-sodium @ 20 g ai ha-1 at 15-25 days after sowing as post-emergence, and then one spot hand weeding at 30-35 days after sowing was effective in controlling weeds. These results suggest that rice yield gaps in eastern India can be reduced, and farmers' income from rice can be increased by more than 50 % by replacing beushening with drill-DSR or precision broadcast-DSR. The results could be applicable to approximately 6.4 million ha of lowland rice where beushening is currently practiced in Eastern India.

15.
Technol Soc ; 59: 101196, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31885408

RESUMO

This paper analyzes smallholder farmers' willingness to pay (WTP) for the purchase of scale-appropriate farm mechanization in the hill ecologies of Nepal using the case of mini-tiller technology: a small, 5-7 horsepower two-wheel tractor primarily used for agricultural land preparation. Using primary survey data from 628 randomly-selected households, we find that farm size, local wage rates, out-migration, access to credit services, and associations with agricultural cooperatives positively influence the WTP for mini-tillers while the number of draft animals owned negatively influence the WTP for mini-tillers. On average, farmers were willing to pay 31% less than the actual price of a mini-tiller. Results also exhibited a heterogeneous demand in which the lowest quartile farm size households, typically the poorest farm households, were willing to pay 26% less for the mini-tiller than the top quartile of farms. In the context of labor scarcity and rising rural wages, agricultural policy on farm mechanization in Nepal should aim to prioritize small farms through robust service provision models in order to increase the level of farm mechanization in the country.

16.
Land use policy ; 85: 104-113, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31217652

RESUMO

Smallholder farmers in the mid-hills of Nepal are facing an acute labor shortage due to out-migration which, in general, has affected the capacity to achieve timely crop establishment, harvest, and inter-cultural operations. These effects are more visible in the case of labor-intensive crops such as rice and promoting higher levels of rural mechanization has emerged as the primary policy response option. Nevertheless, quantitative evidence for the ability of mechanization to offset the adverse effects of shortages increasing labor prices in these systems is largely absent. This study investigates the impacts associated with adoption of mini-tillers (5 to 9 horsepower) for land preparation on smallholder rice productivity in the mid-hills of Nepal. We use an endogenous switching regression that accounts for both observed and unobserved sources of heterogeneity between mini-tiller adopters and non-adopters. Findings demonstrate that rising on-farm rural wage rates and an emerging decline in draft animal availability are driving adoption of the mini-tiller. Among users, the mini-tiller increased rice productivity by 1,110 kg/ha (27%). Further, regression results suggest that mini-tiller non-adopters would be able to increase their rice productivity by 1,250 kg/ha (26%) if they adopt. Moreover, our analysis revealed that very small farms (≤0.25 ha) that adopt mini-tillers are benefited the most in terms of gains in rice productivity. These findings support policies that favor the expansion of small-scale mechanization in the hill production ecologies of South Asia and highlight the need to foster the emergence of an associated service economy that will permit smallholders access to capital-intensive machinery such as the mini-tiller.

17.
Exp Cell Res ; 375(2): 106-112, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30579954

RESUMO

Hexokinase 1 and 2 have been shown to inhibit Bak- and Bax-mediated apoptosis, leading us to combine the histone deacetylase inhibitor romidepsin with clotrimazole or bifonazole, two compounds that reportedly decrease mitochondrial localization of hexokinases. Cancer cell lines derived from breast, kidney, lung, colon or ovarian cancers were treated with a short-term exposure to 25 ng/ml romidepsin combined with either clotrimazole or bifonazole. The combination of romidepsin with 25 µM clotrimazole or bifonazole resulted in increased annexin staining compared to cells treated with any of the drugs alone. Cell death was caspase-mediated, as the pan-caspase inhibitor Q-VD-OPh was found to inhibit apoptosis induced by the combination. A549 lung cancer cells or HCT-116 cells deficient in Bak and Bax were also resistant to apoptosis with the combination implicating the intrinsic apoptotic pathway. We found that a 24 h treatment with clotrimazole or bifonazole decreased total hexokinase 2 expression, resulting in a 76% or 60% decrease, respectively, of mitochondrial expression of hexokinase 2. Mitochondrial hexokinase 1 levels increased 2-fold or less. Our work suggests that the combination of a short-term romidepsin treatment with bifonazole or clotrimazole leads to increased apoptosis, most likely due to decreased mitochondrial expression of hexokinase 2.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Hexoquinase/metabolismo , Histona Desacetilases/farmacologia , Neoplasias/metabolismo , Células A549 , Clotrimazol/farmacologia , Depsipeptídeos/farmacologia , Sinergismo Farmacológico , Células HCT116 , Humanos , Imidazóis/farmacologia , Mitocôndrias/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos
18.
3 Biotech ; 8(7): 304, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30002994

RESUMO

In Indo-Gangetic plains (IGP) of India, natural resources (soil, water, and environment) are degrading under the conventional-till (CT)-based management practices in rice-wheat cropping system. A long-term field experiment was conducted to understand the soil bacterial diversity and abundance under different sets of management scenarios (Sc). The study comprised of four scenarios, namely, -Sc.I CT-based rice-wheat system (farmers' practice); Sc.II, partial conservation agriculture (CA) based in which rice is under CT-wheat and mungbean under zero-tillage (ZT); Sc.III, full CA-based in which rice-wheat-mungbean are under ZT and Sc.IV, where maize-wheat-mungbean are under ZT. These scenarios varied in cropping system, tillage, and crop residue management practices. Using Illumina MiSeq sequencing technology, the variable regions V3-V4 of 16S rRNA were sequenced and the obtained reads were analyzed to study the diversity patterns in the scenarios. Results showed the presence of 53 bacterial phyla across scenarios. The predominant phyla in all scenarios were Proteobacteria, Acidobacteria, Actinobacteria, and Bacteroidetes which accounted for more than 70% of the identified phyla. However, the rice-based systems (Sc.I, Sc.II, and Sc.III) were dominated by phylum Proteobacteria; however, maize-based system (Sc.IV) was dominated by Acidobacteria. The class DA052 and Acidobacteriia of Acidobacteria and Bacteroidetes of Bacteroidia were exceptionally higher in Sc.IV. Shannon diversity index was 8.8% higher in Sc.I, 7.5% in Sc.II, and 2.7% in Sc.III compared to Sc.IV. The findings revealed that soil bacterial diversity and abundance are influenced by agricultural management practices as bacterial diversity under full CA-based management systems (Sc.III and Sc.IV) was lower when compared to farmer's practice (Sc.I) and partial CA (Sc.II) scenarios.

19.
Field Crops Res ; 228: 93-101, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30739981

RESUMO

Nepal is at a crossroads of diminishing farm-labor and inadequate investment into farming operations that, among other factors, have stagnated domestic wheat yield. Cultural and economic constraints have hindered the widespread adoption of more expensive precision agriculture technologies like zero-till that have the capacity to improve labor and farm input efficiencies. To capture the benefits from added precision of application but with the ability to fit within the current semi-mechanized seed bed preparation and tillage system, we introduced a low-cost, chest mounted seed and fertilizer. We found that simple mechanization caused yield efficiencies to be positive and significant for nitrogen and phosphate. Seed rates using this method were positively associated with seedling density. This led to both yield and profit being more predictable for farmers. Conversely, hand-applied inputs caused a disassociation between inputs and end of season yield and therefore added a large measure of risk to their farming operations.

20.
Land use policy ; 60: 206-222, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28050058

RESUMO

Changing dietary preferences and population growth in South Asia have resulted in increasing demand for wheat and maize, along side high and sustained demand for rice. In the highly productive northwestern Indo-Gangetic Plains of South Asia, farmers utilize groundwater irrigation to assure that at least two of these crops are sequenced on the same field within the same year. Such double cropping has had a significant and positive influence on regional agricultural productivity. But in the risk-prone and food insecure lower Eastern Indo-Gangetic Plains (EIGP), cropping is less intensive. During the dryer winter months, arable land is frequently fallowed or devoted to lower yielding rainfed legumes. Seeing opportunity to boost cereals production, particularly for rice, donors and land use policy makers have consequently reprioritized agricultural development investments in this impoverished region. Tapping groundwater for irrigation and intensified double cropping, however, is unlikely to be economically viable or environmentally sound in the EIGP. Constraints include saline shallow water tables and the prohibitively high installation and energetic extraction costs from deeper freshwater aquifers. The network of largely underutilized rivers and natural canals in the EIGP could conversely be tapped to provide less energetically and economically costly surface water irrigation (SWI). This approach is now championed by the Government of Bangladesh, which has requested USD 500 million from donors to implement land and water use policies to facilitate SWI and double cropping. Precise geospatial assessment of where freshwater flows are most prominent, or where viable fallow or low production intensity cropland is most common, however remains lacking. In response, we used remotely sensed data to identify agricultural land, detect the temporal availability of freshwater in rivers and canals, and assess crop production intensity over a three-year study period in a 33,750 km2 case study area in southwestern Bangladesh. We combined these data with georeferenced and temporally explicitly soil and water salinity information, in addition to relative elevation classifications, in order to examine the extent of winter fallows and low productivity rainfed cropland that could be irrigated by small-scale surface water pumps. Applying observations of irrigated crop sowing dates and yields from 510 wheat, 550 maize, and 553 rice farmers, we also modeled crop intensification production scenarios within the case study area. We conservatively estimate that at least 20,800 and 103,000 ha of fallow and rainfed cropland, respectively, could be brought into intensified double cropping using SWI. Scenario analysis indicates that if 25%-75% of the fallow or low-intensity land were converted to irrigated maize, national aggregate production could increase by 10-14% or 29-42%, respectively. Conversion to wheat would conversely boost national production by 9-10% or 26-31%. Irrigated rice is however unlikely to contribute >3%. In aggregate, these actions could generate between USD 36-108 million of revenue annually among farmers. Intensification therefore has important land use policy and food and income security implications, helping to rationalizei SWI investments. Crop choice, water resource allocation, and water governance will however remain crucial considerations for irrigation planners.

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