Response of two varieties of upland rice to fertilizer and its residue in organic farming systems

Abstract

Irrigation water crisis and the conversion of productive land constantly threaten the productivity of rice. The phenomenon of degradation of land productivity due to excessive synthetic chemical fertilizers in the past has contributed to the limiting factor of rice production. Development of organic-based upland rice on dry land is one alternative solution. Organic cultivation of upland rice needs attention so that the empowerment of local input and the fulfillment of food need can be realized. This experiment aims to determine the effect of organic fertilizer types and its residue on growth and yield components of two varieties of upland rice. Experiments were carried out in two planting seasons. The first growing season used a split-plot design. The main plot consisted of chicken manure (20 tons/ha), Centrosema pubescens (4.3 tons/ha) + chicken manure (10 tons/ha), and Tithonia diversifolia (4.3 tons/ha) + chicken manure (10 tons/ha). Subplot consisted of Situ Patenggang and Limboto varieties. The experiment in the second growing season used a split-split plot design. The main plot consisted of 50 and 100% dosage of fertilizer in the first growing season, the subplots are Danau Gaung and Batu Tegi varieties. Chicken manure; chicken manure + C.pubescens; chicken manure + T.diversifolia give the same effect on the productivity of upland rice in the second growing season. Productivity of upland rice in a row according to the treatment were 1.23,1.26, and 1.19 tons/ha. The use of Tithonia diversifolia gives the best effect on some variables of plant growth and plant resistance to pests and diseases. Limboto variety in the first growing season and Batu Tegi variety in the second growing season are varieties that give the best response to organic fertilizer. Danau Gaung and Batu Tegi varieties have similar yield in the second growing season, with the productivity of each variety is 1.25 and 1.22 ton/ha. Dosage of 50 and 100% resulted similar productivity of upland rice, the productivity given by each dosage is 1.28 and 1.19 ton/ha. Combined treatment of type of organic fertilizer and varieties had the same effect on plant productivity. Fertilizer dosage of 50 and 100 % give the same effect on the components of crop yield in the second growing season. The combination of fertilizer dosage, fertilizer types, and varieties only influenced plant height. Chicken manure, C. pubescens and T. diversifolia can be used as the source of organic fertilizer, depending on the level of difficulty in obtaining the material.