Influence of poultry manure on agrophysical condition and fertility of the soils of the Biya-Chumysh upland

Abstract

On a significant area of the Biya-Chumysh Upland of the Altai Region, in arable lands, the agrochemical service points out decreasing thickness of the humus horizon and land acidification, decreasing organic matter content and, consequently, soil compaction occurs. Poultry manure was used as an ameliorant and organic fertilizer. It is a waste of poultry farming, and its volumes are growing every year. The field experiment was conducted on the farm of the SPK “Agrodar”, Zonalniy District of the Altai Region. Poultry manure was applied under spring soft wheat crops at the rates of 5, 10, 15, 20 t ha; the control variant was without any manure. The site consisted of leached medium-humus thin chernozem with neutral pH. Sand and coarse-silt fractions prevailed in the arable soil layer. The soil structure index made 54%. The soil had high content levels of mobile phosphorus and exchange potassium. Under the influence of poultry manure, the pH became slightly acid. Depending on poultry manure application rates, organic matter content (three-year average) increased as following: application rate of 5 t ha - from 4.5% to 4.7%; 10 t ha - to 4.9%; 15 t ha - to 5.3%; 20 t ha - to 5.3%. The gross nitrogen content in the soil in the experimental variants varied in the range of 0.3-0.4%. Over three years, the content of nitrate nitrogen increased; its maximum values were observed at the application rates of 15 t ha (13.8 mg kg) and 20 t ha (12.9 mg kg). Total phosphorus storage increased from 0.188% at the beginning of the experiment to 0.48-0.54% in the variants at the end. Mobile phosphorus content increased substantially at the rate of 15 t ha - up to 269.7 mg kg; and 20 t ha - up to 290.7 mg kg. The total potassium content changed insignificantly - from 2.6% at the beginning of the experiment to 2.72-2.82% at the end in the variants. The content of mobile potassium on average in the variants of the experiment with poultry manure application increased by 12.4-35.8%.