Nutrient Removal by other Field Crops Grown in Reddish Brown Earth Soil in the Dry Zone of Sri Lanka

Abstract

With the harvest of a crop, substantial amount of nutrients is removed from soil. If the Soil’s nutrient level is not replenished by adding fertilizers and manures, fertility status of soil is gradually decreasing and as a result of that soil becomes less productive. Our knowledge about nutrient removal by different crops especially other field crop grown in the dry zone of Sri Lanka is very limited. For the better understanding on fertilizer management, information about nutrient removal by crops is very important. Therefore, the present study was conducted to gather information on nutrient removal by other fi$1d crops grown in dry the zone of Sri Lanka. The field experiment was conducted in MahaIlluppalama on Reddish Brown Earth (RBE) soil during the Matta season with file species of other field crops viz. maize (Cowan), ground nut Tissa), green gram (MI 5), chili (MI 2) and cowpea (Wnruni). Crops were established and maintained according to the Department of Agriculture recommendations. All the crop species re replicated three times, according to the Randomized Complete Block Design. Plant sampling was done after two weeks of plant establishment and at the harvest stage and prepared for laboratory analysis. N, P, K, Ca, Mg, and S of plant samples were analyzed using standard techniques. Statistical analysis was done using SAS software package. Comparison is performed by Turkey's Studentized Range Test comparison. According to the results, differential uptake pattern of nutrients wa5 observed by the crops grown the RBE soil. Almost all crops showed a significantly different nutrient removal at be initial and harvesting stages. A significant quantity of nutrients has been removed by each crop at the harvest stage. N removal by all five crops was ranged from 69.50 to 103.14 kg/ha at the harvest stage. Similarly, the K removal by the five crops also showed a relatively high value which ranged from 64.76 to 185.18 kg/ha. All crops removed relatively low amounts of P which ranged 8.45 to 14.29 kg/ha at the harvesting stage. F 'om the results, it was evident that the considerable quantity of nutrients ha5 been re oved by each crop and provides useful information for efficient use of fertilizer and its application. One way of maintaining soil fertility is to return crop residues back to the field. Therefore, the recycling of residues of the crops after harvesting would be beneficial to maintain soil fertility