Vol. 6, Special Issue 4 (2018)
Soil fertility assessment and mapping of rice super zone, Jhapa
Author(s): SP Vista, SB Kumar, TB Ghimire, S Rai, B Kutu and BK Karna
Abstract: Rice productivity and its plantation area have been increasing in Nepal. This will certainly boost paddy production and bring down the import of rice. Ministry of Agricultural Development has estimated per hectare productivity of paddy in the country to increase to 3.5 tons in 2017-18 against 3.37 tons per hectare productivity recorded in the previous fiscal. However, paddy productivity in Nepal is comparatively low. In order to remain food secured and for enhancing production and productivity of food crops, the Government of Nepal has created pockets, blocks, zone and super zone for particular crop depending on the suitability of the crop according to agro ecological zones. This research aims to assess and prepare soil nutrient map of Rice super zone, Jhapa in Nepal. The specific objectives of the research were to assess soil texture, pH and organic matter status and simultaneously prepare soil fertility map of the rice super zone. A total of 202 soil samples were collected and nutrients were analysed using standard procedure in the soil laboratory. Composite soil samples were collected from 6 to 10 different spots of the area at 0-20 cm depth by using soil auger. The GPS location of each soil sampling point was noted. The soil sampling point of the super zone was determined by studying various aspects (area, slope, colour, texture, etc.) of the area. Based on the laboratory analysis, nutrient maps were prepared. Soil fertility maps were prepared by observing the critical nutrients required for the rice. Results revealed that soil reaction of Rice super zone was mostly found to be medium acidic (mean pH 5.52) which is almost very suitable for rice. Almost all soils of super zone were within the strongly acidic to slightly alkaline pH range that is very suitable for rice. The soil pH ranged from 4.6 to 7.89, but most of the samples showed moderately acidic range and rice can adapt wide range of soil pH. The organic matter content of the soil ranged from 0.4% to 4.06%, ranging from very low to high. Mean organic matter content of the sampled soil is 1.91% which falls under the category of medium. Most of the soils of rice super zone are under the category of medium organic matter content. Total nitrogen in the soils of area falls within the range of 0.02 to 0.2% that are under the category of very low to high. Mean N content is 0.09% that falls under the category of medium. Available phosphorus of the soils, in general falls within the range of 2 to 43 kg per hectare in the category of very low to medium. Mean Phosphorus content of the soil is 10.75 kg per hectare that fall in very low range. This nutrient is critical in rice super zone for rice production. The amount of available potassium in the soils of rice super zone ranges from 107 to 522 kg per hectare falling under the category of low to very high. The mean value of the available potassium in the soil is 224 kg per hectare that falls under the category of medium. Majority of the soils of study area is loam. There is also sandy loam, silty loam and silty clay loam types of soil in the area. Based on the soil analysis report, it could be concluded that the soils of rice super zone is critically low in phosphorus content. Immediate attention should be given to apply phosphatic fertilizer; otherwise this could limit crop production. The soil reaction is fair enough for cultivating rice crop at the moment. Nitrogen, potassium and Organic matter are also in medium range therefore, in order to obtain high production and productivity of rice, organic matter should be added in adequate quantity with sufficient N, P and K fertilizers. Soil fertility maps were prepared by setting criteria based on nutrient status that were tested in the laboratory and on the basis of nutrients that are critical for rice. Rice super zone soil was found having low (89.52%) and medium fertility status (10.04%).
Pages: 157-162 | 688 Views 81 Downloads
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How to cite this article:
SP Vista, SB Kumar, TB Ghimire, S Rai, B Kutu and BK Karna. Soil fertility assessment and mapping of rice super zone, Jhapa. International Journal of Chemical Studies. 2018; 6(4): 157-162.
