Cereals–soybean intercropping is not well studied, despite the importance of these crops in increasing agricultural profitability and ensuring nutritional and food security in Southeast Asia. We compared different intercropping practices (IPs) with monocropping practices (MPs) for their yield and economic performance by small-scale farms without mechanization. The treatments were IPs of rice–maize, rice–soybean, or maize–soybean compared with MPs of rice, maize, or soybean as sole crops, across three provinces in the rainfed areas of western Indonesia with a wet climate. Our results show that the yield advantages using the land equivalent ratio of the IPs were 44% for rice–maize, 54% for rice–soybean, and 63% for maize–soybean compared to MPs. Rice equivalent yield, maize equivalent yield, and the gross margin under IPs were significantly higher per cycle than under MPs; IPs provided a substantially lower cost of production and of paid workers. Compared to just rice, there were additional net return gains of USD 160 and USD 203 ha⁻¹ per cycle under rice–maize and rice–soybean intercropping. Maize–soybean intercropping resulted in an additional net return gain of USD 153 ha⁻¹ compared to just maize. These results suggest there is considerable potential for small farmers to increase their yields and profits by intercropping in rainfed areas with a wet climate.

The purpose of this study was to evaluate (a) the performance of two modern rice varieties (non-tolerant and tolerant for saline soils) under different fertilizer management options, and (b) assess the yield gap and income increase through proper crop and nutrient management at different levels of soil salinity. Experiments were carried out in moderate and high levels of soil salinity in West Java, Indonesia. A split plot design with three replications was used. The main plots included two rice varieties, Inpari-30 Ciherang sub1 and Inpari-34 (tolerant variety for saline soils), and subplots included eight fertilizer management treatments. Farmer participatory field trials were also established across three levels of soil salinity with four different rice varieties, Sidenuk, Inpari 30, Inpari 34, and Inpari 35, and a fertilizer package consisting of organic and inorganic fertilizers. Under low and moderate soil salinities, Sidenuk and Inpari 30 with recommended practice had higher productivity and economic benefit compared to the saline tolerant rice varieties, Inpari 34 and Inpari 35. However, under high soil salinity, the yields of Inpari 34 and Inpari 35 with recommended practice were 93% higher than farmers’ practice, representing an exploitable yield gap of 1.3 t ha⁻¹ and benefit above fertilizer cost of USD 301 ha⁻¹. The combination of tolerant varieties and improved nutrient management use for rice production can therefore be used as a strategy for improving farmers’ income and livelihoods in coastal areas of Indonesia.

The CORIGAP project was implemented in six main rice granaries in South and Southeast Asia. The project introduced several country-specific sustainable best management practices, including nutrient management, pest management, water management, and several postharvest technologies, among other specific practices. This chapter introduces each country and its respective challenges to rice production. It outlines cultivation practices, historical developments, and their impacts on opportunities for the development of the rice sector. This is accompanied by specific case studies that highlight the adoption of specific technologies and practices. Case studies encompass the adoption of various best management practices in Myanmar and Thailand, especially postharvest technologies. Furthermore, the chapter highlights the outreach of “One Must Do, Five Reductions” in Vietnam, the development and implementation of the “Three Controls Technology” and alternate wetting and drying (AWD) practices in China, rodent pest management in Indonesia, and weed and water management in Sri Lanka. These case studies identified positive agronomic, social, and economic changes. The chapter concludes by harnessing the agricultural development strategies in each country with a synthesis of outcomes and impacts.

Primary risk to rice (Oryza sativa L.) production is salinity intrusion and water scarcity, leading to a shortage of irrigation water and yield reduction. We examine the impact’s effects of alternate wetting and drying (AWD) vs. continuous flooding (CF) and microbe application on yields of three rice cultivars (Ciherang, Inpari 34 Salin Agritan, Inpari 35 Salin Agritan) grown under slight and moderate soil salinity in the dry season (DS) 2017 and 2018. Under slight soil salinity, AWD and CF had nonsignificant difference in grain yield. Under a moderate soil salinity level, there was a substantial decrease in grain yield (8.2%), number of productive tillers, seeds panicle^-1, and weight of 1000 grains with the plants grown under AWD. Increased soil salinity levels resulted in lower yield reduction with microbial than without microbial treatments. ‘Ciherang’ showed superiority over ‘Inpari 34’ and ‘Inpari 35’ under AWD at slight soil salinity. However, the yield reduction in the moderate salinity level was more remarkable for ‘Ciherang’ (18.1%) than ‘Inpari 34’ and ‘Inpari 35’ (9.7%) as salinity-tolerant varieties. The AWD used almost one-third less irrigation supplement than CF. This greatly assists small farmers in reducing the additional cost of pumping water. On average, AWD improved total water productivity by 32.7% under slight and 20.4% under moderate soil salinity over CF. Here, we lay out the potential for small farmers in slight salinity lowlands areas of the northern coast of Java to apply AWD during the DS. Farmers could manage water efficiently to prevent further yield loss and improve farm profitably.

Climate change threatens rice production, making early-maturing rice varieties an important adaptation strategy. However, information on optimal technology packages for maximizing the productivity of these varieties remains limited. This study aimed to assess the effects of different technology packages on yield and yield components and to determine which package showed the most favorable performance across early-maturing rice varieties. A nested split-plot design was employed, consisting of two planting patterns (Jajar Legowo and square planting), three early maturing rice (Cakrabuana, Inpari 13, and M70D), and five fertilizer management packages. Analysis of variance revealed that fertilizer management significantly affected plant height, panicles per clump, weight per panicle, number of total grain, weight of 1000 grain, and yield. Planting pattern significantly influenced total tiller number and panicles per clump, whereas varietal effects were significant only for the number of total grain. Yield showed strong positive correlations with weight per panicle (r = 0.65**), number of total grain (r = 0.59**), and weight of 1000 grain (r = 0.51**). The highest yield under the Jajar Legowo was achieved by Cakrabuana supplied with 100 kg ha−1 trichocompost, 3.3 mL L−1 biofertilizer, 100 kg ha−1 non-subsidized urea, and 300 kg ha−1 subsidized NPK fertilizer, reaching 6.67 t ha−1, whereas the highest yield under square planting was recorded in M70D receiving 100 kg ha−1 subsidized urea and 300 kg ha−1 subsidized NPK fertilizer, reaching 5.89 t ha−1. Overall, the Jajar Legowo combined with 100 kg ha−1 non-subsidized urea and 300 kg ha−1 subsidized NPK fertilizer, with or without 100 kg ha−1 trichocompost, represented the most suitable technology package for improving the productivity of early-maturing rice varieties, particularly Cakrabuana.