Sustainability analysis of existing land-use systems in northeast Thailand

Soil fertilityLand useSustainabilityWatershedsVillagesFertilizersCrop productionSugarcaneRice

Recent Changes in the Composite Swidden Farming System of a Da Bac Tay Ethnic Minority Community in Vietnam's Northern Mountain Region

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました

Limits Imposed by Management in Rainfed Farming Systems

WHEN the Asian Productivity Organization (APO) held a meeting in Chiang Mai, Thailand, in November 1980 to discuss the production of food legumes in Asia, it highlighted that over the previous decade food legume production in the region had remained constant or declined despite growing demand (Suzuki and Konno 1982). The symposium attributed the slow growth in production to slow expansion in the area planted to food legumes, and to low yield per unit area. Poor economic returns and unfavourable government policy towards legumes relative to other crops like rice and wheat discouraged ex~ansionin the area cultivated. while low prod-uctiviiy was blamed on inadequate water (mostly rainfed crops), marginal land, and low production inputs, e.g. fertilisers, disease and insect control. A meeting (organised by ACIAR, ICRISAT, and IRRI) was then held at ICRISAT Centre in December 1985 to review the progress on Asian Regional Research on Grain Legumes (ARRGL) and to develop plans for future cooperation. It was revealed that much of the food legumes are still rainfed and grown on marginal lands. In India, rainfed agriculture represents 75% of the arable land or 108 million hectares, and even if current efforts to bring more area under irrigation were successful, at least 45% of the arable area will remain rainfed by the year 2000 (Guatam 1P83). The situation is more or less the same in most Asian countries. Clearly, if a significant increase in food legume production is to be realised, production of the crops in rainfed farming systems will have to be improved

Pre-chill with gibberellic acid overcomes seed dormancy of Jerusalem artichoke

Jerusalem artichoke is a valuable source of inulin, a polysaccharide. Inulin is a sustainable source of dietary fiber that enhances the immune system in humans. Although Jerusalem artichoke can be propagated vegetatively, breeders use cross-fertilization to produce novel varieties and hybrids with higher inulin yields. Seed dormancy can hinder the breeding progress because dormancy reduces the number of generations a breeder can obtain in one year. Current methods for breaking seed dormancy are time-consuming, and usually involve removing or pin-pricking the seed coat of these very small seeds, or using several weeks of seed vernalization or several months of storage. Breeders thus require better methods that are less time-consuming and achieve higher germination percentages. Here we studied germination, dormant seed, dead seed and the seedling growth rate of different Jerusalem artichoke genotypes and seed lots after seeds were treated with different methods to break seed dormancy. We evaluated fresh and stored seed lots using the following treatments: seed samples were planted on top of media moistened with either potassium nitrate, gibberellic acid or distilled water as control. Two identical sets of samples were planted: one set was germinated in a chamber at alternate 15−25 °C for 28 days, while the second set was prechilled at 5 °C for 14 days, before moving the samples to the alternate 15−25 °C chamber for 14 days. Our findings reveal that the highest germination percentage up to 85.3% was obtained when applying pre-chill with gibberellic acid. This novel dormancy-breaking treatment was thus effective in promoting fresh seed germination

Role of Legumes in Improving Soil Fertility and Increasing Crop Productivity in Northeast Thailand

Northeast Thailand constitutes one-third of total area of the whole country and one-third of the total population live in this region. The income of the majority of the people living here is below half of the national average mainly due to low agricultural production and productivity. The low agricultural productivity of the northeast region compared to other regions of Thailand is attributed mainly to erratic rainfall, water shortage during the dry season, undulating terrain and poor and marginal soils. The soils in the region are mostly sandy in texture with low soil moisture holding capacity. The soils are also very low in organic matter and low in general fertility

Quantifying Yield Gaps and Abiotic Stresses in Rain-fed Production Systems of Thailand: Global Theme on Agroecosystems Report no. 45

Quantifying potential yield and yield gap of crops for various growing conditions could provide valuable information for designing strategic crop management plans to increase crop yields. The farmers in the Phu Pha Man district of Khon Kaen province of Thailand commonly grow soybean and peanut under both rainfed and irrigated conditions and cultivate maize under rain-fed conditions. The farmers’ long-term average yields in the district are 1360 kg ha-1 for soybean, 1480 kg ha-1 for peanut and 2810 kg ha-1 for maize. The simulation results, using CSM-CROPGRO models for soybean, peanut and maize, showed that for the Phu Pha Man district, the yield potential of soybean ranged from 1130 to 3700 kg ha-1, maize ranged from 1370 to 7460 kg ha-1 and peanut ranged from 630 to 3880 kg ha-1 under rain-fed conditions. For the fully irrigated conditions in the dry season, the yield potential of soybean ranged from 1870 to 3150 kg ha-1 and peanut ranged from 1840 to 3010 kg ha-1. The yields were generally higher for early planting dates than for later plantings. These results indicated that farmers’ yields under rain-fed conditions in the Phu Pha Man district can be more than doubled with improved management practices. Yield gap analysis for Tad Fa watershed in Phu Pha Man district of Khon Kaen showed that under soil water and nitrogen nonlimiting conditions, the yield potential of soybean ranged from 2810 to 3630 kg ha-1 and for maize, it ranged from 4360 to 6130 kg ha-1. The yield reductions from the yield potential caused by water and nitrogen limitations ranged from 12% to 48% for soybean and 29% to 83% for maize. Low rates of nitrogen application and pests and diseases were the main factors causing yield gaps of soybean and maize in the Phu Pha Man district. Regional analysis of peanut yields showed that northeastern region of Thailand is more productive area for rain-fed conditions, whereas northern region is more suitable to produce peanut under well-irrigated conditions during the dry season

Application of the Cropping System Model (CSM)-CROPGROSoybean for Determining Optimum Management Strategies for Soybean in Tropical Environments

The determination of optimum crop management practices for increasing soybean production can provide valuable information for strategic planning in the tropics. However, this process is time consuming and expensive. The use of a dynamic crop simulation model can be an alternative option to help estimate yield levels under various growing conditions. The objectives of this study were to evaluate the performance of the Cropping System Model (CSM)-CROPGROSoybean and to determine optimum management practices for soybean for growing conditions in the Phu Pha Man district, Thailand. Data from two soybean experiments that were conducted in 1991 at Chiang Mai University and in 2003 at Khon Kaen University were used to determine the cultivar coefficients for the cultivars CM 60 and SJ 5. The CSM-CROPGRO-Soybean model was evaluated with data from two experiments that were conducted at Chiang Mai University. The observed data sets from farmers’ fields located in the Phu Pha Man district were also used for model evaluation. Simulations for different management scenarios were conducted with soil property information for seven different soil series and historical weather data for the period 1972–2003 to predict the optimum crop management practices for soybean production in the Phu Pha Man district. The results of this study indicated that the cultivar coefficients of the two soybean cultivars resulted in simulated growth and development parameters that were in good agreement with almost all observed parameters. Model evaluation showed a good agreement between simulated and observed data for phenology and growth of soybean, and demonstrated the potential of the CSM-CROPGROSoybean model to simulate growth and yield for local environments, including farmers’ fields, in Thailand. The CSM-CROPGRO-Soybean simulations indicated that the optimum planting dates from June 15 to July 15 produced maximum soybean yield in a rainfed environment. However, the planting date December 15 produced the highest yield under quality irrigation. Soybean yield was slightly improved by applying nitrogen at a rate of 30 kg N ha)1 at planting. Soybean yield also improved when the plant density was increased from 20 to 40 plants m)2. The results from this study suggest that the CSM-CROPGRO-Soybean model can be a valuable tool in assisting with determining optimum management practices for soybean cropping systems in the Phu Pha Man district and might be applicable to other agricultural production areas in Thailand and southeast Asia

Improving Management of Natural Resources for Sustainable Rainfed Agriculture in Northeastern Thailand

Lands of northeastern Thailand are sloping and fragile. A large proportion of these soils are degraded due to soil erosion. Degraded soils are one of the major constraints for agricultural production in this region. ICRISAT in collaboration with the Department of Agriculture, Land Development Department, and Khon Kaen University, Thailand started a project in 1999 with the financial support from the Asian Development Bank to improve the management of natural resources for sustainable rainfed agriculture through integrated watershed approach. This paper summarizes all the research work carried out for three years during the project period. This includes selection of benchmark site in the ecoregion, baseline surveys, establishment of monitoring devices and various interventions in cropping systems, land and water management and fertility management areas, and human resource development. The initial results of research indicate a reduction in soil erosion and improvement of crop yields due to various interventions. There is sufficient scope to scale up this work in the ecoregion. The details of various activities undertaken and the outputs are presented in the pape

Genetic Relationships of Crown Rust Resistance, Grain Yield, Test Weight, and Seed Weight in Oat

Integrating selection for agronomic performance and quantitative resistance to crown rust, caused by Puccinia coronata Corda var. avenae W.P. Fraser & Ledingham, in oat (Avena sativa L.) requires an understanding of their genetic relationships. This study was conducted to investigate the genetic relationships of crown rust resistance, grain yield, test weight, and seed weight under both inoculated and fungicide-treated conditions. A Design II mating was performed between 10 oat lines with putative partial resistance to crown rust and nine lines with superior grain yield and grain quality potential. Progenies from this mating were evaluated in both crown rust-inoculated and fungicide-treated plots in four Iowa environments to estimate genetic effects and phenotypic correlations between crown rust resistance and grain yield, seed weight, and test weight under either infection or fungicide-treated conditions. Lines from a random-mated population derived from the same parents were evaluated in three Iowa environments to estimate heritabilities of, and genetic correlations between, these traits. Resistance to crown rust, as measured by area under the disease progress curve (AUDPC), was highly heritable (H = 0.89 on an entry-mean basis), and was favorably correlated with grain yield, seed weight, and test weight measured in crown rust-inoculated plots. AUDPC was unfavorably correlated or uncorrelated with grain yield, test weight, and seed weight measured in fungicide-treated plots. To improve simultaneously crown rust resistance, grain yield, and seed weight under both lower and higher levels of crown rust infection, an optimum selection index can be developed with the genetic parameters estimated in this stud