Converting Upland Rice Fields to Rice Terraces in slope area is one of an alternative rice planting system for sustainable rice cultivation on the mountainous area in the upper northern of Thailand. It can produce double yield compared with those of upland rice. However, soil fertility should be considered when first converted. Therefore, rice nutrient management by Omission Plot Technique has been studied. Results in wet season 2011 found that yield from applying phosphorus in combination with potassium chemical fertilizer (+PK or -N) was not significantly different from applying nitrogen, phosphorus and potassium combination (+NPK) and as same as non phosphorus (+NK or -P) or non potassium application (+NP or -K) in which always showed significantly... |