Site-specific Fertilizer Management on Growth, Yield, and Agronomic Nitrogen Use Efficiency of Rice Grown in Sapphaya Soil Series

Abstract

A field experiment was conducted in the farmer field on Sappaya Soil Series with the aim to determine growth characteristics, grain yields and agronomic fertilizer use efficiency of Pathum Thani rice variety. The experimental design was a randomized complete block design with six replications. Treatments were five fertilizer management practices: (1) no fertilization (control), (2) farmer practice’s fertilization (F), (3) site-specific fertilization (SSF), (4) fertilization at two folds of SSF (2SSF) and (5) fertilization at three folds of SSF (3SSF). The results showed that the numbers of tillers per plant at 30 days after transplanting and the heights of plants at 50 days after transplanting of the F treatment were significantly highest (P<0.05). The numbers of tillers per plant of the 3SSF treatment at 50 days after transplanting was numerically greatest (14.25 tillers per plant) but did not significantly differ (P>0.05) from the F treatment (14.04 tillers per plant). However, both were significantly greater (P<0.05) than the others. Grains per spike (99.38 grains) and grain yields (1,195.25 kg/rai) of the rice were significantly highest (P<0.05) in the F treatment. However, with regards to agronomic nitrogen use efficiency and economic returns, the SSF treatment significantly outweighed (P<0.05) the other treatments. In conclusion, soils must be evaluated chemically before growing Pathum Thani rice on Sappaya Soil Series and with the SSF fertilizer practice, the rice can provide increased grain yields and subsequently economic returns.