Land suitability evaluation for rice and maize based cropping systems using FAO maximum limitation approach

Abstract

Despite the growing interest in irrigated agriculture in Malinyi District in Morogoro Region, its practice in Kilosa kwa Mpepo traditional irrigation scheme remains low in production and productivity compared with medium to modern irrigated agriculture. Since construction of medium to modern irrigated agriculture is expensive, matching crop requirement with resources available through land suitability evaluation is necessary to improve production and productivity in the area. Such important study however,ha.s not been undertaken in Kilosa kwa Mpepo traditional irrigation scheme proposed for modernization. This study, evaluates the land suitability of Kilosa kwa Mpepo traditional irrigation scheme for rice (Oryza sativa L.) and maize (Zea mays L.) cropping systems using FAO maximum limitation method. After matching land qualities with land use requirements, results indicated that soil wetness, soil physical characteristics, and soil fertility status were the major limiting factors affecting land quality within the proposed irrigation scheme. Results also showed that of the total area surveyed (i.e. 1,117 Ha) 25% was rated as highly suitable (S1), 37% as moderately suitable (S2) and 37% as marginally suitable (S3) for irrigated rice based cropping systems. However, after controlling floods the highly suitable (S1) to marginally suitable (S3) land observed was to a large extent related to soil physical property, leading to inadequate capacity to retain nutrients. Similarly, results of land suitability for irrigated maize based cropping systems indicated that of the total study area, 37% was rated as highly suitable (S1) and 63% as moderately suitable (S2). The moderately suitable land in the surveyed area was related to soil physical property and poor soil fertility status (i.e. texture and low pH). Taken together, these data suggest that well-designed irrigation infrastructures along with flood protection band and drainage structures may control and or reduce the incidence of floods and waterlogging conditions in the study area. Long-term fertility management requires consideration of use of organic materials such as manure and compost. Such programs need to maximize use efficiency and minimize environmental losses. Implementation of the proposed approach to optimizing land management will reverse the suitability of land from marginally suitable to highly suitable land thus delivering a range of socio-economic and agro-environmental benefits to the farmers in Kilosa kwa Mpepo village in Malinyi District