Green Global
Foundation   Journal
...an emerging window for scientific research and publication across the globe

ASSESSMENT OF SOIL FERTILITY QUALITY IN PADDY CULTIVATED AREA (CASE STUDY: SOUTHERN HALF OF FOUMANAT PLAIN IN NORTH OF IRAN) (Pages : 1 - 10)

Improving crop productivity and resource use efficiency is necessary to ensure food security and environmental quality. For producing a high-quality soil fertility map the fuzzy technique in geographic information systems (GIS) was used to optimize nutrient input rates. Two soil fertility qualities were considered: Inherent soil fertility potential (the thickness of plow layer, clay content, CEC, organic C, EC and pH) and nutrient availability (soil nutrient-supplying capacity for N, P and K). The descriptive statistics were calculated for each property in SPSS 17.0. The semi-variance calculations and semi-variogram model fitting were performed using GS+ version 5.1 software for geostatistics analysis. Based on R2 and residual sums of squares (RSS), soil N, K, OC, CEC, EC and pH were modeled best with spherical relationship, in addition P and clay with exponential relationship. Then ordinary kriging procedure was used for mapping in Arc GIS 9.3. The cross-validation analysis was conducted by using mean of error (ME) and root mean of squared error (RMSE). Results showed that most of the investigated area had a moderate inherent fertility potential and were in low class of nutrient availability for intensive rice production. Due to their lower inherent potential and nutrient content, most of the study area in the western parts may not be suitable for further intensification of rice production. Especially low available K seems to be the major constraint to high rice yield. Further yield increases will require improved adjustment of P fertilizer rates according to the soil P status. According to the results, better nutrient management practices based on soil nutrients status to optimize the required inputs are necessary.Download