Studi Penurunan Kekuatan Geser Tanah Lempung Indramayu Akibat Pupuk Kimia

Abstract

. Green revolution which is started on 1960 and came into Indonesia on 1972, have earned to overcome threat lacking of global food, but side effects of its execution also can be felt in this time that is balance of natural ecosystem. Using of chemical fertilizer continuously without controlled have been changed soil composition so that behavior of the soil also follow to change. To that's this research is made, that is knowing effects of chemical fertilizer content in the soil to shear strength of soil. Samples of soil taken from land one of the gristle slide area in West Java that is Indramayu's clay. Type of soil is clay with rate 45,.92% Halloysite, 25,34% montmorillonite, specific gravity 2,58, liquid limit (LL) 74,26% and Plasticity Index 46,39%. Samples of soil made with optimum water content and chemical fertilizer type used are Urea, TSP and NPK with rate 0,01%, 0,1%, 0,5% and 1%, and period of curing 0, 1, 3, 7 and 14 day. Shear strength test for samples used unconfined compression test (UCS) and UU Triaxial test used as control. Resulting from this research indicate that with existence of chemical fertilizer content in the soil have change plasticity and strength of soil. Shear strength effect of soil that happened from this chemical fertilizer is more chemical fertilizer content in soil more reduce value of shear strength progressively and this degradation increase along with increasing time of curing. Degradation of value of qu biggest happened on soil with TSP, caught up by soil with Urea, then soil with NPK