Tạp chí
Võ Thị Gương, Jean Claude Revel (trang 26-32, 47)
Từ khoá: đánh giá, khả năng, cung cấp, dưỡng chất, đất lúa, đất, lúa, Đồng bằng sông Cửu Long
Summary
Assessment of nutrient supply capacity of the rice soil in the Mekong Delta
Based on the results of field experiment in dry season at 19 sites on 4 soil types, used in situ ion exchange resin capsules soil test to measure N, P, K released during 2 weeks at the panicle stage of rice. The principal component analysis, PCA, showed that K/Na and Ca/Mg are 2 major factors, which explained 50.3% of the variation of rice yield. The 2nd factor, K/Mg and K/CEC explained 33% of the variation. Therefore, the imbalance of cation nutrition in soil can be yield-limiting factor for rice. High yield was found in rich soils, which suppled 69-77% total N plant uptake. Low rice yield group in acid sulfate soil and degraded soil supplied only 41%. A boundary line fitted through the upper rim of the data points provided by a double-exponential model can be used to predict the potential indigenous supply of soil and plant nutrient uptake.
