Case studies of super yield in the soybean variety Tszhun Khuan 35

Abstract

The article discusses examples of record soybean yields in the variety Tszhuan Khuan 35.

Objective. Analysis of cases of record yields (over400 kg/mu, or 2.8 t/ha), investigation of mechanisms of this phenomenon and creation of a cultivation technology model of such harvests.

Study Conditions. In 2008-2012 the soybean variety Tszhuan Khuan 35 was grown in eight different locations of natural zones of China. The seeding rate was 20,000 / mu (300,000 / ha). Several irrigations with top dressing were conducted during the growing season.

Results. To obtain record soybean yields the optimal combination of three factors is necessary - variety / environmental conditions / growing technology. The variety Tszhuan Khuan 35 is characterized as a highly adaptive one with high potential yield capacity. It is resistant to lodging, with leaves of medium size contributing to good sun lighting of the whole crops. Such varietal features contribute to successful cultivation of Tszhuan Khuan35 in thickened crops.

Environmental conditions in growing areas are also favorable for record yields, in particular, high solar radiation (5,300 mJ/m²), which accelerates processes of photosynthesis, and, therefore, synthesis of organic compounds and accumulation of biomass  in soybean.

     In addition to thickening crops high yields are affected by watering with dressing, more specifically, 12 irrigations with fertilizers and micronutrients in small doses. Besides, soybean plants were treated with the preparation "Shou Jie An" shortening internode length and the growth stimulator "Ai Mi Ting".

The influence of physiological parameters was assessed, in particular leaf area index (LAI), photosynthetic potential (LAD), net photosynthetic productivity, and balance of plant organs.

Conclusions. The studies found that the achievement of record soybean yields in the variety Tszhuan Khuan 35 was promoted by its morphological peculiarities (resistance to lodging, tolerance to thickening), environmental conditions (high solar radiation, difference between day and night temperatures), elements of cultivation technology (multiple watering with dressing in small doses, stimulators), and physiological parameters of plants of the variety Tszhuan Khuan 35. Thus, the balance of plant organs as a specific distribution of biomass in the variety Tszhuan Khuan 35 is the following: 16.6 % in leaves, 9.4 % in petioles, 14.8 % in stems, 19.6 % in pod shells, and 39.6 % in seeds, unlike the theoretical values of 30 %, 10 %, 20 %, 10 %, and 30 %, respectively. Therefore, the biomass of vegetative organs - leaves, petioles, stems - was lower than the theoretical distribution, and the biomass of reproductive organs - pods, seeds – much higher. This peculiarity of the soybean variety Tszhuan Khuan 35 is one of the causes of record yields.