Nitrogen, phosphor, and potassium nutrients uptake of soybean (Glycine max (L.) Merril) on three levels of radiation intensities and soil moisture content of latosol

anglais. An experiment was implemented from July to August 1994 in greenhouse of the Ecophysiology Division, Bogor Research Institute for Food Crops using a split-split plot design with three replications. Radiation intensity levels as main plot were: without shelter, 25 percent shelter, and 67 percent shelter. Levels of available water in soil as sub-plot were: less than 25 percent soil water availability, content of soil water availability, and 125 percent soil water availability. Soybean varieties as sub-sub plots were: Wilis, Malabar, and Lokon. The experiment showed that nitrogen and phosphor uptake of Wilis was the highest, 41.228 mg and 1.225 mg per hill, especially under 100 percent light intensity and soil water availability more than 25 percent. Under 25 percent shade the potassium uptake of Wilis was 45.997 mg, this was higher than Malabar. The highest increased in seed dry weight, up to 0.733 g, occured if soil water content changed from available water to 125 percent water content. One calory decreased in radiation caused 0.006 g decreased in seed dry weight per hill, Malabar variety produced an average of 0.892 g seed dry weight, where each millimeter of water will increased 2.0 mg of dry seed weight. Malabar variety had water use efficiency of 0.043 percent g/ml and radiation use efficiency 0.011 percent g/cal. Malabar variety produced the heaviest 100 good seed (7.293 g), followed by Wilis variety (5.520 g) and Lokon variety (4.597 g)

indonésien. Penelitian dilaksanakan dari bulan Juli sampai September 1994 di rumah kaca kelti ekofisiologi Balai Penelitian Tanaman Pangan, Bogor. menggunakan rancangan petak terpisah dengan tiga ulangan. Taraf intensitas radiasi surya ditempatkan sebagai petak utama, masing-masing tanpa naungan (100 persen), ternaungi 25 persen dan ternaungi 67 persen. Sebagai anak petak taraf ketersediaan air, masing-masing: kadar air tanah 25 persen kurang dari air tanah tersedia (53 mm), kadar air tanah tersedia 63 mm, dan kadar air tanah 125 persen dari air tersedia (73 mm). Sebagai anak-anak petak adalah 3 varietas kedelai: Wilis, Malabar, dan Lokon. Hasil penelitian menunjukkan bahwa varietas Wilis menyerap nitrogen dan fosfor tertinggi, 41,228 mg dan 1,225 mg/rumpun, terutama pada perlakuan tanpa naungan dan kandungan air tanah tersedia 2 persen. Varietas Wilis pada perlakuan ternaungi 25 persen menyerap hara kalium 45,997 mg lebih tinggi dibanding varietas Malabar. Peningkatan rata-rata berat kering biji tertinggi 0,733 g terjadi apabila kandungan air tanah berubah dari kandungan air tanah tersedia menjadi 125 persen. Sedangkan penurunan setiap kalori intensitas radiasi surya menyebabkan penurunan berat kering 0,006 g/rumpun. Varietas Malabar menghasilkan berat kering biji rata-rata 0,892 g, yang mana peningkatan setiap mililiter air meningkatkan rata-rata berat kering biji 2,0 mg serta memiliki nilai efisiensi pemanfaatan air sebesar 0.043 persen g/ml dan efisiensi pemanfaatan radiasi surya sebesar 0,011 persen g/kal. varietas Malabar menghasilkan berat 100 butir biji kualitas baik tertinggi 7,432 g, kemudian diikuti oleh varietas Wilis 5,520 g dan varietas Lokon 4,597 g