Keefektifan tindakan konservasi tanah dan air dengan metode vegetatif dalam menekan aliran permukaan dan erosi tanah pada pertanaman kakao (Theobroma cacao L.)

Abstract

Cacao plant is one of the major commodity of plantation in South East Sulawesi, especially in Konawe regency. Land management practices which is implemented by the local farmers on cultivating cacao, in many cases are not according to soil and water conservation principles. The research was aimed to study the effectiveness of several soil and water conservation practices on reducing runoff and soil erosion on cacao plantation with different land slopes and canopy coverages. The research was conducted in Amosilu village, Besulutu district, Konawe regency, the province of South East Sulawesi, from December 2006 to September 2007. The Experimental method in the field study was split plot design consisting three factors. The first factor was slope consisting two levels (10 – 15% and 40 – 45%) and the second factor was age of the cacao plant consisting two levels (5 to 7 month and 25 to 27 month) were used as main plots (P1 = 5 to 7 month and 10 – 15%; P2 = 25 to 27 month and 10 – 15%; P3 = 5 to 7 month and 40 – 45%; and P4 = 25 to 27 month and 40 – 45%), while the third factor, the vegetative conservation treatment was used as sub plots consisting three levels, i.e T1 = cacao with ground cover, T2 = upland rice and soybean rotation within cacao plant, T3 = upland rice and soybean rotation within cacao plant + Arachis pintoi as strip cropping. There was not interaction effect both cacao plant and slope treatment with vegetative conservation treatment on runoff and soil erosion with soil properties, exception on aggregate stability index. The result showed that vegetative conservation treatment (T3) with upland rice and soybean rotation within cacao plant with A. pintoi as strip cropping was best alternatif because it has been produced the lower rate of erosion (21,76 ton ha-1 year-1) compared tolerable soil loss value (22,44 ton ha-1 year-1) and improved of soil properties and has given a good benefit to famers from both upland rice and soybean.