Characteristics of saline soil and effect of fertilizer application to rice yield

Characteristics of saline soil determine the rice yield along the seaboard. High concentration of dissolved salt decreases growth and rice yield. The study aimed to evaluate physical and chemical characteristics of saline soil in Sidoarjo and Surabaya, East Java, Indonesia. The result analysis of soil exchangeable Na+, K+, Ca++, and Mg++respectively was 0.8-1.94; 0.33-2.73; 16.32-20.4, 1.83-8.88 me.100g-1.The value of soil pH was 7.35- 7.55, EC value of soil was 0.64-1.83dS.m-1, and the content of organic-C was between 1.1-2,4,6 %. The result of soil characterization was then crosschecked with the rice yield in saline soil by weighing dry rice grains per clump. The rice yield was 3-4.1 ton.ha-1 and negatively correlated to the exchangeable values of Na, SAR, bulk density and dust content. It was positively correlated with organic-C, fertilizer, exchangeableof Ca++, Mg++, and K+, as well as soil's CEC. The ratio value of Ca:Mgnamely2.2-8.2, and K:Mgnamely0.18- 0.21 exceeded the limit of ideal value and caused low production. The rice yield was negatively correlated with the content of exchangeableNa+, values of pH and EC. It achieved more than 4 ton.ha-1when added with 300-450 g.plant-1 of organic materials and 1.0-1.3 g.plant-1 of NPK.