Decision Support Systems in Agriculture: Some Successes and a Bright Future

Non

Acid Sulfate Soils: Their Characteristics, Genesis, Amelioration and Utilization(<Special Issue>Problem Soils in Southeast Asia)

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。This paper reviews the characteristics, occurrence, distribution, amelioration and utilization of acid sulfate soils. Emphasis is placed on acid sulfate soils in Thailand and related areas to which references could be found. Data on amelioration relate to rice cultivation, while discussions of management and utilization extend to other crops and fish ponds

Refining and disseminating site-specific nutrient management technology in Thailand

International audienc

Refining and disseminating site-specific nutrient management technology in Thailand

The development of site-specific nutrient management technology for maize in Thailand began in 1997. The site-specific nutrient management technology was simplified by using soil test kits in the field, field identification of soil series and subsequent referencing of soil properties by soil series, and by organizing and developing a site-specific recommendation with a decision aid. The second aspect of the conceptual approach was not only to simplify the technology but also to empower and build farmer capacity. The dissemination process was modified in 2002 to increase farmer empowerment by identifying and empowering farmer leaders. The two main components: (1) simplifying the agricultural technology and (2) building farmer capacity resulted in higher maize yields and profit by the farmers. Increased self-reliance, a better standard of living, more knowledge of crop production, soil improvement and networking of the farmer associations were all observed. The SimCorn software was developed to aid decision-making by providing on-site calculations of the Nitrogen, Phosphorus and Potassium (NPK) fertilizer recommendations using soil series identification and soil test kit results. Assistance in calculating the bulk blending of fertilizer was also given in the software. Techniques designed to empower farmers were tested and found to be effective. These techniques included social mapping to identify farmer leaders, sharing knowledge, knowledge capture and management, and scaling up of the improved knowledge and capability. Farmer leaders learned to implement site-specific nutrient management and to disseminate the technology to other farmers in their community. The farmer leaders obtained not only better income but improved soil and water management for sustainable agriculture. The technology was initially developed for maize production systems but was extended to rice and sugarcane farmer leaders as well

Predicting Phosphorus Buffer Coefficients of Thai Flooded Rice Soils Using Soil Properties

ABSTRACT To quantify a more precise phosphorus (P) requirement prediction by the phosphorus decision support system (PDSS), the most important factor in PDSS equation, the phosphorus buffer coefficient (PBC) was studied. The use of clay content as a predictor of PBC prediction might not be suitable when applied with Thai flooded rice soils. Ten flooded rice soils were collected to study the PBC estimated by Bray-2 (PBC Bray-2 ), Mehlich-1 (PBC Mehlich-1 ) and iron oxide-impregnated filter paper method or Pitest (PBC Pi-test ). Multiple regression was used to study the relationship between PBC and soil properties which involved P sorption process. The results indicated that PBC Bray-2 correlated with organic matter and iron determined by citrate-bicarbonate-dithionite method (Fe d ) (adjR 2 =0.87) whereas PBC Mehlich-1 correlated with Fe d (adjR 2 =0.73). Unlike those two chemical extractions, PBC Pi-test correlated with iron determined by ammonium oxalate pH 3 in darkness (Fe o ), aluminum determined by citrate-bicarbonatedithionite method (Al d ) and soil pH (adjR 2 =0.93). However, the study suggested that the PBC should be estimated by Pi-test so that the model would allow more accurate PBC prediction