Residual effect of NPK on rice for soybean grown after lowland rice

English. Research aimed to know the effect of urea bricket for lowland rice and residual effect of macro elements (especially NPK) for soybean productivity after rice was conducted at the Research Installation of Legume and Tuber Crops at Genteng (rice during dry season-1 1996 and soybean during rainy season-2 1996), and Kendalpayak (rice during dry season-2 and soybean during rainy season 1996/1997). Split plot design with three replications were used in those two locations. Four fertilization packages (NPK combination) including the use of urea bricket, were applied for rice as main plot; while sub plot were fertilizer application on soybean after rice (consist of six NPK combinations). The result showed that the application of urea bricket fertilizer did not improve yields components and yield of rice. On the soil having high P and medium K status, application of P and K fertilizer for rice did not absolutely needed. The average of grain yield (in the form of dry grain milling) at the Genteng and Kendalpayak were 3.92 and 3.86 t/ha, respectively. Residual effect of fertilizer on rice and its interaction effect with fertilizer application to soybean were significant for soybean seed yield at Genteng, while there were not interaction effect of both factors at Kendalpayak. Without any additional fertilization, soybean seed yield at Genteng and Kendalpayak were 1.44 and 1.20 t/ha, respectively; which was planted after lowland rice where soil P and K status were medium to high, fertilizers application for soybean after rice were not needed because it did not increase seed yield

Indonesian. Di Indonesia kedelai ditanam setelah padi sawah mencapai sekitar 65 persen dari total areal panen pada pola padi-padi-kedelai atau padi-kedelai-kedelai. Penelitian untuk mengetahui pengaruh pupuk urea terhadap padi sawah serta residu pupuk NPK pada padi sawah terhadap produktivitas kedelai setelah padi telah dilakukan di Inlitkabi Genteng (padi MK-1 1996-kedelai MK-2 1996) dan di Inlitkabi Kendalpayak (padi MK-2 1996 - kedelai MH 1996/1997). Percobaan menggunakan Rancangan Petak Terbagi diulang 3 kali. Empat paket pemupukan (kombinasi NPK), termasuk penggunaan pupuk urea tablet, diterapkan pada tanaman padi (sebagai petak utama), sedangkan sebagai anak petak adalah enam perlakuan kombinasi pupuk NPK yang diberikan langsung pada kedelai setelah padi. Hasil percobaan menunjukkan bahwa penggunaan pupuk urea tablet tidak meningkatkan komponen dan hasil tanaman padi. Pada tanah dengan status kadar P tinggi dan K sedang, pemupukan P atau K untuk tanaman padi tidak diperlukan. Rata-rata hasil gabah kering giling di Genteng dan di Kendalpayak masing-masing 3,92 dan 3,86 t/ha. Di Genteng, ada interaksi antara pengaruh residu pupuk dari padi maupun dengan pemupukan langsung pada kedelai terhadap hasil biji kedelai sedangkan di Kendalpayak, tidak ada interaksi. Tanpa pemupukan langsung pada kedelai, hasil biji kedelai yang dicapai di Genteng adalah 1,14 t/ha, dan di Kendalpayak 1,20 t/ha, masing-masing tidak berbeda dengan perlakuan pemupukan yang lain. Disimpulkan bahwa pemupukan langsung pada tanaman kedelai tidak mampu meningkatkan hasil biji. Oleh karena itu, maka pemupukan pada kedelai setelah padi sawah yang dipupuk secara intensif tidak diperlukan karena tidak meningkatkan hasil kedelai