Analsis Status Hara Fosfor Pada Berbagai Lahan Pertanian Pangan di Pulau Jawa

Abstract

Indonesia is an agricultural country that has the fourth largest population in the world with 237,6 million people and growth rate of 1,49%. One program that made by the government to fulfill the demands of food is agricultural intensification program. While using the improved varieties, fertilizing is one of the most important input to succed this program. In Indonesia, P fertilizer is the second most important after N fertilizer, especially on up land. Availability of phosphorus in the soil becomes very important because it has many roles in plants. However, in the soil, their availability relatively low because of binding by Al, Mn and Fe in acid soils, or by Ca, Mg in alkaline soil. Since it is easily fixed and the presence of P in the soil is limited but needed in large quantities, the role of P fertilizer is critical in maintaining the availability of P nutrient for plant growth. The phenomenon levelling off, which is the rate of increase in soil productivity is not in line with the rate of fertilizer is the main reason to evaluate the status of the current P nutrient in agricultural soils in Java. This study aimed to evaluate the status of the current P nutrient (available-P and potential-P) in agricultural lands in Java, and their association with some other soil chemical properties. There are 43 samples (locations) were taken from the island of Java, which consists of 23 samples of paddy field and 20 samples of up land agriculture. The methods that used to measure the potential-P is HCl 25% extraction and the available-P is Bray 1. The results based on the available criteria show that from 23 samples of paddy field, 19 samples have very high status of potential-P, two samples have high status and two other samples have low status of potential-P. In the paddy field available-P there are 21 samples that have very high status and two other samples that have high and low status of available-P. On up land agriculture, from 20 samples, 15 samples have very high status of potential-P, four samples have high status and one other sample have medium status. Available-P in up land agriculture entirely have very high status. For paddy field there are positive correlations between available-P with exch-Ca, and pH, meanwhile on up land agriculture, potential-P has positive correlations with total-C, total-N, and EC. From this study, it is concluded that the status of P in agricultural soil in Java is in general very high. In the future, it is worthed to consider how to harvest especially the potential-P for plant growth.