DAMPAK PEMANFAATAN PUPUK ORGANIK TERHADAP SIFAT FISIK TANAH DALAM BUDIDAYA SINGKONG LAHAN PESISIR SELATAN KABUPATEN JEMBER

Abstract

Coastal land is a marginal land that has a low soil productivity as a result of loose soil structure, low water holding ability, high infiltration and evaporation, low fertility, low organic matters, high temperatures and strong winds, low cation exchange capacity and high infiltration. Excessive availability of air in the pores causes drying and oxidation of organic materials to run fast. In 2014, in the southern coastal area of Jember Regency had experiments on cassava cultivation been conducted from January 2014, with a variety of organic fertilizer treatments such as: control, liquid organic fertilizer, fish hydrolyzate fertilizer, and manure. However, the research only examined the productivity of cassava and did not investigate the physical and chemical properties of the soil that affected the productivity of cassava plants. The physical properties have either direct or directly impacts and control the growth of plants, roots, oxygen, and temperature. This research aimed to study the impacts of the utilization of organic fertilizers on coastal land by the cultivation of cassava on the physical properties and productivity of cassava in Southern coastal area of Jember Regency. The results of this research expected to provide information to stakeholders to support the government's plan to increase the production of one of the major food crops and to use of biofuel as an alternative energy. The research was conducted in Southern coastal area which is an iron ore mining area in Paseban Village, District of Kencong. Cassava plant variety used was local variety Kaspro. In experiments, several kinds of organic fertilizers were used (Hydrolysate Fish, Nasa, Manure) given at the beginning of cassava planting when the crop was 14 days after planting. Analysis of changes in soil physical properties (BJP, BV, porosity, ability to hold water, and distribution of aggregates) and analysis of crop production (weight of fresh tubers, dry tuber weight, weight of fresh skin, and weight of dry skin) was conducted after the treatment when the plants were 12 months , Soil physical properties and crop production were tested with BNT level of 5%. Organic fertilizers (Nasa, fish hydrolyzate, and Manure) were given at the beginning of planting, they did not significantly affect the physical properties of the soil (BJP, BV, and distribution of aggregates). The porosity of soil was also not significant, but at the end of planting of cassava (11 months after planting) it indicated to decrease the soil porosity by 3.8% compared to control. The use of organic fertilizers had not affected the ability of soil ability to hold water even though there was an indication that the use of manure increased soil ability to hold water by 7.06% higher than the control. On crop production parameters, a variety of organic fertilizers had significantly different results. The productivity of cassava in the control was 5.8 tons/ha, whereas in the treatment of liquid organic fertilizers Nasa, fish hydrolyzate fertilizer, and manure resulted in the average productivity of cassava by 21 tons/ha, 13.6 tons/ha, and 17.2 tons/ha or increased by 134.48 to 268.96% compared to the productivity of cassava in control.