The use of soil ameliorants to improve soil quality and crop productivity of degraded semi-arid upland in Gunung Kidul, Yogyakarta, Indonesia

Abstract

Optimization of degraded semi-arid upland needs to be done by improving soil fertility and quality, as well as increasing plant resistance to drought. The purpose of this research is to evaluate the effect of balanced fertilization and soil ameliorant on soil quality and crop productivity. The study was conducted on degraded semiarid upland in Gunung Kidul Regency, Yogyakarta, Indonesia at the beginning of the dry season in 2018. Randomized block design with five treatments and four replications was applied. The treatments consisted of TP: control (farmer management), T1: Balanced fertilization recommendation, T2: T1+Biochar SP-50, T3: T1+Bio-silica, T4: T1+Biochar SP-50+Bio-silica, and T5: T1+Vulkanorf K-424. Soil ameliorant treatment had a positive effect on water aggregate stability. Treatment of Biochar SP-50 in combination with Bio-silica had a positive effect on soil bulk density, aeration pore, and water availability pore. Balanced fertilization accompanied by Biochar SP-50 (without and with bio-silica) gave a positive effect on the content of soil organic C and K-potential. Plant growth of balanced fertilization+Biochar SP-50 was significantly higher than other treatments, while maize production among treatments did not show a significant difference. Therefore, it requires long-term and continuous treatment to improve soil quality and crop productivity in degraded land.