Assessment of two soil fertility indexes to evaluate paddy fields for rice cultivation
This article (PDF) in the Journal Sustainability assesses two soil fertility evaluation approaches in paddy fields for rice cultivation, in order to develop a user-friendly and credible soil fertility index (SFI). Also the study aimed to identify specific soil limitations, as well as to determine and map the soil suitability of the study area for rice cultivation. A parametric approach and a fuzzy method with adapted criteria definition tables, were used to compute SFI. The study results demonstrated that both of the methods provide reliable and valuable information. Compared to the fuzzy method, the procedure of the parametric method is easier but may be expensive and time-consuming. However, the fuzzy method, with carefully chosen indicators, can adequately evaluate soil fertility and provide useful information for decision making. According to the two methods used in the study, the majority of the study area was classified as moderately suitable for rice cultivation. The results also demonstrated that the most important limiting factors were drainage and the thickness of the plow layer. The other limiting factors were texture, pH, organic matter and coarse fragment. The appropriate recommended management practices suggested to overcome these limitations and upgrade the suitability for increasing rice production include: increasing the thickness of the plow layer, application of sufficient water and fertilizer, improving the low levels of organic matter content of the soil in the area, and suitable conservation measures.