Pemberian Air Terbatas pada Tanah Ultisol dengan Tekstur Lempung Berpasir Berdasarkan Pertumbuhan Tanaman Kedelai ( Glycine maxL. )

Abstract

Deficit irrigation is to provide enough water for need plants based on the period of plant’s growth. Plant’s growth is affected by filed capacity that depends on the texture and organic matter of soil. The objective of this research was to study the effect of deficit irrigation based on growth and yield of soybeans at ultisol soil with sandy loam. The observed parameters were soil texture, organic matter, N-total, P-available, pH, porosity, evapotranspiration, number of seeds per plant, weight per grain, seed weight per plant, wet weight and dry weight of plants. The results showed that ultisol soil with sandy loam texture had organic matter, N and P were classified as very low, pH slightly acidic, good porosity and relatively constant evapotranspiration. The number of seeds per soybean plant ranged from 60,166-78,333 fruits/plants, the weight per seed of the soybean plant ranged from 0,120-0,158 g/plant, seed weight per soybean plant ranged from 7,219-12,376 g / plant, the wet weight of soybean plants ranged from 17,401-26,428 g/plant and the dry weight of soybean plants ranged from 4,82-6,64 g/plant.

Pemberian air terbatas adalah memberikan air secukupnya yang diperlukan tanaman berdasarkan periode pertumbuhan tanaman tersebut. Pertumbuhan tanaman di pengaruhi oleh kapasitas lapang yang bergantung pada tekstur dan bahan organik tanah. Tujuan penelitian ini untuk mengetahui pengaruh tingkat pemberian air terbatas terhadap pertumbuhan dan hasil tanaman kacang kedelai pada tanah ultisol dengan tekstur lempung berpasir. Parameter yang di amati meliputi, tekstur tanah, bahan organik, N- total, pH, porositas, evapotranspirasi, jumlah biji per tanaman, bobot biji per butir, bobot biji per tanaman, bobot basah, dan bobot kering tanaman. Hasil penelitian menunjukkan tanah ultisol tekstur lempung berpasir memiliki kandungan bahan organik, N dan P di klasifikasikan sangat rendah, pH masam, porositas baik, dan evapotranspirasi relatif konstan. Jumlah biji per tanaman kacang kedelai berkisar 60,166-78,333 buah/tanaman, bobot biji per butir tanaman kacang kedelai berkisar 0,120-0,158 g/tanaman, bobot biji per tanaman kacang kedelai berkisar 7,219-12,376 g/tanaman, bobot basah tanaman kacang kedelai berkisar 17,401-26,428 g/tanaman, dan bobot kering tanaman kacang kedelai berkisar 4,82-6,64 g/tanaman.