PENGARUH MIKORIZA DAN AMELIORAN PADA BAWANG PREI DI LAHAN TERCEMAR ABU VULKANIK

Erupsi Gunung Sinabung di Kabupaten Karo Provinsi Sumatera Utara memberikan dampak kurang baik terhadap kesuburan lahan dan kualitas hasil pertanian. Pencemaran abu vulkanik menyebabkan terjadinya penurunan pH tanah, peningkatan kadar Fe dan S, serta pemadatan tanah. Kegiatan penelitian pemberian bahan amelioran pupuk kandang dan kapur dolomit serta mikoriza pada bawang prei telah dilaksanakan di lahan tercemar abu vulkanik, di Desa Sirumbia, Kecamatan Simpang Empat, Kabupaten Karo sejak Mei hingga Oktober 2015. Hasil penelitian menunjukan bahwa pada lahan yang tercemar abu vulkanik, pemberian bahan amelioran seperti pupuk kandang dan kapur dolomit atau mikoriza perlu dilakukan untuk meningkatkan produktivitas lahan. Tanpa pemberian bahan-bahan tersebut pertumbuhan dan hasil tanaman ternyata lebih rendah. Hasil bawang prei segar tertinggi yaitu sebesar 20,83 t/ha diperoleh dari pemberian 100% pupuk Urea, SP-36 dan KCl dengan dosis masing-masing sebanyak 400, 200 dan 150 kg/ha, yang diikuti dengan penambahan pupuk kandang 5 t/ha, dolomit 500 kg/ha dan mikoriza sebanyak 10 g/tanaman. Pemberian pupuk dan mikoriza berperan dalam meningkatkan produktivitas tanaman yang dibudidayakan pada lahan tersebut dan pada gilirannya akan meningkatkan pendapatan petani. ABSTRACT The Effect of Mycorrhiza and Ameliorants on Leek Crops in the Volcanic Ash Contaminated Lands. Eruption of the Sinabung volcano in Karo district, North Sumatera province produced the unfavorable impact to the fertility of land and quality of agricultural products. The volcanic ash pollution caused soil pH reduction, the increasing level of Fe and S, and the soil compaction. A study on the application of ameliorant materials of manure, dolomite lime and mycorrhiza to leek crops was conducted in the contaminated land by volcanic ash, which was in Sirumbia village, Simpang Empat sub district, Karo district from May to October 2015. The results showed that in the contaminated land by volcanic ash, the application of ameliorant materials such as manure, dolomite lime or mycorrhiza were necessary without the application of these materials, the crop growth and yield were significantly lower than with application. The highest yield of leek was 20.83 t/ha produced by the application of 100% fertilizers i.e Urea, SP-36 and KCl up to 400, 200 and 150 kg/ha respectively and it was followed with the addition of 5 t/ha manure, 500 kg/ha dolomite lime and 10/single plant.  The application of mycorrhiza and fertilizers could increase crops productivity cultivated in the erupted land, thus it also can increase farmers’ income.