Researches regarding the influence of fertilization on grains yield and quality at Sorghum bicolor L. in the pedoclimatic conditions from the Center of Moldova

Abstract

Crop fertilization has beneficial effects on the productivity of sorghum crops although the species does not have high demands on it. This is explained by the fact that the root system of sorghum is well developed and manages to extract nutrients from the soil. Previous experiments show that mineral fertilizers contribute to the production increase with 40%. Under A.R.D.S. Secuieni pedoclimatic conditions, for a five years period (2013 – 2017) the influence of nitrogen and phosphorus fertilizers on the soil production and quality was studied, and the conclusion was that sorghum reacts well to the fertilization with these fertilizers. Significant production increases have been achieved in the variants fertilized with doses starting from 80 kg a.s./ha of nitrogen and phosphorus, and the maximum level was recorded in the variant fertilized with 120 kg a.s./ha of nitrogen and phosphorus. Of the five years of experimentation, the most favorable for sorghum crop was 2013, a year characterized as very warm. This year's average production was high and reached 7397 kg/ha. In each of the five years of experimentation, the maximum yield was achieved in the variants fertilized with 120 kg/ha and its variation ranged between 5506 kg/ha (2015) and 7397 kg/ha (2013). The minimum yield level was recorded each year in the non-fertilized variants, ranging from 3842 kg/ha (2014) to 4517 kg/ha (2017). The highest production increase per 1 kg of active substance fertilizer was obtained each year in the variants fertilized with 40 kg a.s./ha of nitrogen and phosphorus. The nitrogen and phosphorus fertilization has also influenced the grain quality, which had a positive influence on the protein content and a negative influence on the starch content.