Status and prospects of conservation farming systems development in limestone upland soils, Brantas watershed

anglais. Farming systems development in upland limestone soils was conducted using a land management strategy which combined civil engineering and vegetative conservation efforts. Since 1985, four conservation models have been tested, i.e. Model A (existing farm practices), model B (bench terrace system), model C (ridge terrace system), and model D (individual terrace system). Research suggests that the productivity of models B and C were higher than models A and D. The average net income of model A farm was Rp. 543,800,-/ha/year, model B : Rp. 1,003.700,-/ha/year, model C : Rp. 909,600,-/ha/year, and D : Rp. 185,700,-/ha/year. In models B and C erosion rates decreased below the tolerable soil loss threshold, but in models A and D erosion is still above the threshold. Most farmers only partially adopt technology packages preferring components which produced short-term benefits such as cropping patterns, high yielding varieties, fodder and livestock systems, and vegetative conservation efforts. It seems difficult for farmers to fully adopt packages because of constraints faced such as capital and family labor. Cropping patterns adjusted to meet the specific demand for commodities which have higher economic value such as soybean, ground nut, chilly, and onion. These can have positive impact in soil fertility when well managed because farmers use more manure and get higher benefits from conservation farming practices.

indonésien. Sistem usahatani yang dikembangkan di lahan kering berkapur adalah sistem pengelolaan lahan dengan mengkombinasikan teknik konservasi secara mekanik dan vegetatif dalam suatu pola usahatani terpadu. Sejak tahun 1985, telah diuji empat model usahatani konservasi, yaitu model A (sistem petani), model B (sistem teras bangku), model C (sistem teras gulud), dan model D (sistem teras individu). Hasil pengujian menunjukkan bahwa model B dan C produktivitas usahataninya lebih tinggi dibandingkan model D dan model A. Pendapatan bersih rata-rata dari model A sebesar Rp.543.800,-/ha/tahun, model B sebesar Rp.1.003.700,-/ha/tahun, model C sebesar Rp.909.600,-/ha/tahun, dan model D sebesar Rp.185.700,-/ha/tahun. Penurunan tingkat erosi sampai dibawah batas ambang laju erosi terjadi pada model B dan C, sedangkan pada model A dan D erosi tanah juga menurun tetapi masih diatas ambang batasnya