Spatial Variability of Soil Factors Affecting Irrigated Lowland Rice Yield

Abstract

Spatial variability of soil chemical and physical properties, and its influence on leaf nutrient content, and yield components were studied in a 0.95 ha rice field in Kuala Selangor. A total of 120 soil samples at 15 cm depth and 120 samples of rice plant were taken at harvesting stage based on grid point sampling of 10m x 10m. The studies revealed that coefficients of variation for soil physical properties were in the order of bulk density > soil moisture > clay content. Soil chemical properties showed coefficients of variation in the order of K > Mg >total-N > CN ratio> P> Ca > total-S > total-C and Cu > Zn > Na > Mn > pH. The coefficients of variation for leaf nutrient content were found to be in the sequence of Cu > Zn> P > K> Mg > N > Na > Mn > Ca. The range for soil physical properties was found to be in the order of bulk density (134 m) > soil moisture (100 m) > clay content (17 m), while the range for soil chemical properties was in the sequence of Mg (21 8 m) > total-C (161m) > pH (134 m) 2: total-S (134 m) 2:P (134 m) > Ca (120 m) > total-N (54 m) > CN ratio (46 m) > Na (41 m) > Mn (35 m) > Cu (20 m) > Zn (15 m).