Potassium fertilization and nutrients dynamics in the soil and in peanut plant at Mediteran upland area

إنجليزي. The pod yield of peanut in Mediteran upland area is always low because of low P and K nutrients within the soil and very low effective of P and K fertilization. The research was conducted in Mediteran upland area at Malang, East Java, during rainy season 1999/2000. The objective of the research was to study the effectiveness of phosphorus and potassium fertilizers on peanut plant, the dynamics of nutrients within the soil, the nutrients absorption by plant and its influence on peanut yield at Mediteran upland area. A factorial randomized block design with three replications were used in this experiment. It had 16 treatments as the combination of two nitrogen fertilizers (urea and ZA), two phosphorus fertilizer rate (0 and 100 kg SP36/ha) and four potassium fertilizer rate (0, 50, 100 and 150 kg KCl/ha). Kelinci variety was used in this experiment and sown in a 4 m x 4 m plot size with plant arrangement of 40 cm x 20 cm and two seeds per hole. The research showed that the soil fertility is not too bad, the rate of C organic matter, P and K nutrients available within the soil were at medium level. Application of urea and ZA similarly increased pod yield and seed quality. Application of ZA fertilizer increased S and P nutrients available within the soil of about 400 percent and 23 percent, respectively, as well as the absorption of S and P nutrients by plant by 19 percent and 30 percent. Application of 100 kg SP 36/ha was necessary to increase pod yield and seed quality. Application of 50 kg KCl/ha was needed for plant growth and development and pod yield increase. Application of 100 kg KCl/ha was only needed for increasing seed quality. Application of 150 kg KCl/ha would decrease pod yield

الأندونيسية. Pada MT 1999/2000 telah dilakukan penelitian efektivitas pemupukan P dan K terhadap hasil kacang tanah di lahan kering tanah Mediteran. Penelitian dilakukan di Kec. Bantur, Kab. Malang, Jawa Timur. Percobaan menggunakan rancangan acak kelompok faktorial, tiga ulangan. Terdapat 16 perlakuan yang merupakan kombinasi dua jenis pupuk N (urea atau ZA), dua dosis pupuk P (0 dan 100 kg SP36/ha) dan empat dosis pupuk K (0, 50, 100, dan 150 kg KCl/ha). Percobaan menggunakan varietas Kelinci yang ditanam dengan jarak tanam 40 cm x 20 cm, 2 tanaman per lubang pada petak perlakuan berukuran 4 m x 4 m. Hasil penelitian menunjukkan bahwa pemupukan N (urea atau ZA) tidak meningkatkan hasil kacang tanah atau kebernasan biji. Namun demikian, pemupukan 100 kg ZA meningkatkan kadar S dan P dalam tanah saat panen masing-masing 400 persen dan 23 persen dan meningkatkan serapan hara S dan P oleh tanaman masing-masing sekitar 19 persen dan 30 persen. Pemupukan 100 kg SP36/ha diperlukan untuk meningkatkan hasil kacang tanah dan kebernasan biji. Pemupukan 50 kg KCl/ha optimum meningkatkan pertumbuhan tanaman, pembentukan polong dan hasil kacang tanah. Sedangkan pemupukan 100 kg KCl/ha hanya optimum meningkatkan kebernasan biji, dan pemupukan 150 kg KCl/ha cenderung menurunkan hasil kacang tanah. Untuk mencapai hasil kacang tanah yang optimal, ketiga jenis pupuk N, P, K agar diberikan bersama-sama karena antara ketiganya ada indikasi saling berinteraksi