Conservation agriculture for sustainable intensification in South Asia

Abstract

outh Asian agriculture is a global 'hotspot' for contemporary and future climate vulnerability. Further, 1.7 billion people live in South Asia, and by 2050, that number is expected to rise to 2.4 billion. Although the region enjoys high economic growth, it suffers from extreme poverty, undernourishment and the deterioration of natural resources 1 . South Asia has more than 42% of the world's poor (earning less than US$1.90 per day), about 21% of the population is undernourished, and more than 41% of children are underweight 2 . Rapid population growth will increase the demand for cereals by about 43% between 2010 and 2050. Meeting this projected need is doubly challenging considering 94% of the land suitable for farming is already in production and 58% of agricultural areas face multiple climatic hazards such as water shortage and extreme heat stress 3 . The present situation is anticipated to worsen with climate change, with rising temperatures and changing monsoon rainfall patterns projected to cost India 2.8% of gross domestic product 4 . Although global crop productivity has more than doubled during the past decades, negative impacts on environment, biodiversity, soil quality and air quality are common 5,6 .Future food production in South Asia requires new management approaches that are efficient and climate smart to make tangible contributions to the United Nations' Sustainable Development Goals (SDGs). Conservation agriculture (CA) has emerged as an alternative to an inefficient tillage-based conventional agriculture. CA is an ecosystem approach to regenerative sustainable agriculture and land management based on three interlinked principles: (1) continuous no or minimum mechanical soil disturbance, (2) permanent maintenance of soil mulch (crop biomass and cover crops) and (3) diversification of cropping system (economically, environmentally and socially adapted rotations including legumes and cover crops), along with other complementary good agricultural production and land management practices 7 . CA helps in managing agroecosystems for improved and sustained productivity, increased profits and food

No-Till Farming and Conservation Agriculture in South Asia – Issues, Challenges, Prospects and Benefits

“…Similarly, Sapkota et al (2015) could not estimate any changes or reduction in N 2 O emissions between ZT and CT plots and therefore the global warming potential (GWP) reduced by 33.5% in CA2 and 12.4% in CA1 than CT. Similarly, rice showed lower GWP as compared to wheat (Jat et al, 2020). However, Kumar et al (2018) contrasted the results as the GWP of rice recorded almost three times than that of wheat although GWP of rice in CT was higher than CA practices.…”

“…SA agriculture is especially vulnerable to climate change (Chattaraj et al, 2014) and therefore, known for global hotspot of future climate vulnerability (Jat et al, 2020). CA practices are widely promoted in SA countries as it is expected to be more resilient to weather-induced stresses owing to climate change (Jat et al, 2012;Bhattacharyya et al, 2018).…”

“…CA practices are widely promoted in SA countries as it is expected to be more resilient to weather-induced stresses owing to climate change (Jat et al, 2012;Bhattacharyya et al, 2018). As rice-wheat cropping systems is the largely adopted cropping system in SA countries, most of the GHG emission studies from CA practices are concentrated in rice-wheat system (Kumar et al, 2018;Sapkota et al, 2018;Jat et al, 2020). While comparing the GHGs emissions from CA and CT practices, Jat et al (2020) revealed CH 4 emission reduction by 12.8% in CA1 (ZT direct seeding in either crop in a system) and 75.2% in CA2 (ZT direct seeding in both crops in a system) than CT.…”

Agricultural Innovation and Sustainable Development: A Case Study of Rice–Wheat Cropping Systems in South Asia

“…Adaptation of innovative agricultural practices, such as conservation agriculture (CA), improves and sustains the productivity of RWCS and preserves scarce natural resources, such as water, energy, environmental quality, time, and labor [58]. The adaptation of CA-based systems is most beneficial in extreme climatic conditions, mitigating the negative impact of climatic stresses, such as water and heat stress, and increasing crop yields (0.4-0.8 t ha -1 per season), when compared with the conventional system [59].…”

“…Using zero tillage (ZT) wheat in RWCS benefits the timeliness of wheat sowing and economics when compared with conventional tillage [59,76]. Zero tillage improves soil health and enhances nutrient concentrations at the soil surface Table 4 [77,78].…”