Low Soybean Productivity Research Articles

Agronomic Feasibility of a Continuous Double Crop of Winter Wheat and Soybean Forage in the Southern Great Plains

In the southern Great Plains, dryland double‐cropping soybean [Glycine max (L.) Merr.] after winter wheat (Triticum aestivum L.) could provide quality summer forage, partially offset mineral fertilizer N applied to winter wheat, and lessen soil erosion. Waiting for wheat grain to mature, however, delays soybean planting and subjects growth to dry and hot conditions. Planting soybean after a hay crop of wheat was investigated to determine the feasibility of the system as a source of livestock feeds and N uptake by both crops. Twelve treatment combinations of two wheat fertilizer N levels (0 and 112 kg N ha−1) and six summer management treatments (fallow: conventional and no‐till; soybean: grazed, cut for hay, green manure, and mulch) were arranged in strips across four replications. Soybean biomass ranged from 1.35 to 1.90 Mg ha−1 when soybean grazing and harvest occurred at seed fill, and crude protein ranged from 129 to 220 g kg−1 resulting in a 3‐yr average N uptake of 44 kg ha−1 Within each N fertilizer level, average wheat forage yields were not different, but yield increased 29% with N fertilizer and crude protein was inversely related to yield. Double‐cropped soybean failed to offer any yield‐enhancing N benefit to wheat or enhance soil N and C content after 3 yr, even when used as a green manure. Unless a producer is willing to accept the low productivity of soybean as a double crop with wheat, the feasibility of this dryland double‐crop forage system is limited.

Keragaan Hasil dan Daya Toleransi Genotipe Kedelai di Lahan Sulfat Masam

High soil acidity is one of the problems caused low soybean productivity on acid sulphate soil. Using tolerant variety is one effort for increasing soybean productivity on acid sulphates oil. The objective of these researches were to understand the performance yield and tolerancy of soybean genotypes to acid sulphate soil. These researches were conducted on acid sulphate soil at Pindahan Baru. Jajangkit Timur and Talaran-Barito Kuala District of South Kalimantan in wet season of 2003/04. These researches were arranged in Randomized Completely Design with three replications. Five genotypes and 4 varieties were evaluated for their tolerance and yield potential. The result showed that none of the genotypes have yield higher than that of check varieties Lawit, Menyapa and Sibayak. There was one of genotypes i.e. Msc 9234-D-3 give higher yield than check varieties Tanggamus, good seed quality and tolerant to acid sulphate soil. Key words: Performance, Soybean, Acid sulphates oil

The Influence of Ascorbic Acid on Growth and Production of Soybean (Glycine max (L.) Merril) Under Drought Stress Condition

The low productivity of soybean in Indonesia was caused by natural factors, biotics, cultivation techniques and soybean plant physiology. Extensification program to meet the needs of soybeans can be solved by using dry land, of drought stress. The study was conducted at the Screen house Faculty of Agriculture, Universitas Sumatera Utara, Medan (± 32 meters above sea level), on July to October 2017, using a randomized block design with 2 treatment factors. The first factor is drought stress with 3 levels ie 80% ; 60% and 40% field of capacity(FC) . The second factor is an ascorbic acid with 4 levels of concentration ie: 0 ; 100 ; 200 and 300 ppm.. The observed of variables ie number of leaves, total leaf area, dry seed weight per plant, 100 seed weight and harvest index. The results showed that the increased treatment of drought stress (80 – 40% FC) had the significant on all observed variables. The Ascorbic acid treatment no significant on all observed variable with the average number of leaves and the highest total leaf area at use 200 ppm ascorbic acid and the lowest at control treatment. The interaction no significant on all observed variable.