Limitation and Recommendation for Rice Cultivation on the Problem Soils in the Southern Region of Vietnam

Background: Soil degradation is the factor causing crops yield decline in the Southern region of Vietnam. Since the recommendations for limitation of soil constraints will consult the proper problem soil management. Methods: The soil limitation identified based on soil chemistry, physics and morphology properties, suggested by Sanchez et al (1998 and 2003). Soil data of 28 field experiments were analysed. Result: There were 25 rice soil fertility classes, among those, CC (clay in top and subsoil) and CCs (clay in top and subsoil, saline affected) types occupied in large areas. The major soil limitation for rice cultivation including soils low in % organic carbon (o); high in P fixation and high Fe toxicity potential (i); potential salinity (s-); low available P (p); low pH and high Al (a); actual acid sulphate soils (c, c-) potential acid sulphate soils (f, f-). The leaching soil toxicity, application of N, P, K fertilizers and organic matter were recommended.