ĐÁNH GIÁ HIỆU QUẢ PHÂN HỮU CƠ VI SINH ĐA CHỨC NĂNG ĐẶC CHỦNG CHO CAO SU GIAI ĐOẠN KIẾN THIẾT CƠ BẢN

The reclaimation of rubber plantation land by the type of organic manures especialy micro-organic fertilizer is one of the most effective measures to improve fertility of soil and ensure the growth and development of rubber trees. Therefore, to select the appropriate type of fertilizer for rubber in growing period is necessary. The experimental results showed that multi-functional micro-organic fertilizer KT1 has composition: peat 50%, agricultural residues 45%, muck 5%, rate (%) N: P: K la 1:1,5:1; additional MgO, Ca, S, Mn, Fe, Mo, B, Zn, Cu, respectively: 2.0%, 0.2%, 0.2%, 0.02%, 1.5 ppm, 15ppm, 20ppm, 10ppm, 3ppm; Phantien trace elements fertilizer 0.2% is most suitable for rubber in growing period. In Lai Chau province when the rubber was manured fertilizer KT1 then the diameter of trunk rubber increased highest (4.60 cm); at Dien Bien province was 5.06 and 5.08 cm; in Son La province was 4.58 cm (the control treatment was 3.50 to 3.96cm). When replacing a part of inorganic fertilizer by KT1 fertilizer then the growth and development of rubber was still well: In Lai Chau province when the rubber was manured fertilizer KT1 and decreased 30% N, 40% P, 70% K; in Son La and Dien Bien manured KT1 and decreased N 30%, 50% P, 40% K then the diameter of trunk rubber increased equivalent with manure 100% NPK fertilizer. The processes of using multi-functional micro-organic fertilizer KT1 for rubber in growing period has improved.