Efektivitas Pupuk Pk Dan Frekuensi Pemberian Pupuk K Dalam Meningkatkan Serapan Hara dan Produksi Kacang Tanah di Lahan Kering Alfisol

ABSTRACT P and K nutrients are very important on producing of peanut pod beside for metabolism prosess in the plant. Higly Ca ion consentration within the soil would decrease PK nutrients absorbtion by plant and decrease of producing the pod. For increasing the effectivity of PK fertilizer application in Alfisol upland, two set experiments were conducted in Malang, East Java at planting time 2002 and 2003. Factorial Randomized block design, three replications was used in these experiments. The treatments of first trial were combination of two N fertilizer (Urea and ZA), three levels of P fertilzer (0, 50 and 100 kg SP36/ha) and three frequency of KC1 fertilizer application (lx2xand 3x application). The treatments of second trial were combination of two N fertilizers (Urea and ZA), three levels of K fertilizer (50, 100 and 150 kg KC1/ha) and three frequencys of K fertilizer application like on first experiment. The dosage of N fertilizer was 12.5 kg N/ha. The treatment plot size was 4 m x 6 m. The result showed that application of ZA was better than Urea on P, K and S nutrients absorbtion by plant, and increased the dry pod yield about 51 %. Application of P fertilizer did not effective on increasing of peanut yield Application of 50 kg SP36/ha increased P nutrient absorbtion by plant just only 15 % and increased dry pod yield just only 10 %. Application 100 kg SP36/ha increased P nutrient absorbtion just only 7 % and did not increase pod yield. The dosage optimal of KC1 fertilizer for increasing the pod yield was 100 kg KO/ha by one time application at planting time. Application of 100 kg KC1/ha increased K and P nutrients absorbtion by plant about 10 % and 15 % respectively if applicated togather with 50 kg SP36/ha, or 28 % and 23 % respectively if applicated togather with 100 kg SP36/ha. Key words: Peanut, PK fertilization, productivity, Alfisol uplan