Study of the effect of sapropel with natural moisture content on soybean yield under extreme moisture shortage

Achieving high crop yields depends largely on weather conditions, which change from year to year. As a result of soil degradation processes in Ukraine, the humus content has decreased by almost a third and is still decreasing. One of the ways to replenish the humic complex of the soil is to apply organic fertilisers, in particular organic sapropel. The positive effect of sapropel fertilisers on the components of soil fertility has been confirmed by many studies. It is also known that mined sapropel has a high moisture content, which ranges from 92–98% for its organic type. The addition of sapropel with natural moisture content ensures the formation of an additional moisture reserve in the soil. The effect can be achieved by local application of sapropel, for example when soybeans are sown using strip-till technology. This paper presents the methodology and results of a study of the effect of organic sapropel with natural moisture content on soybean yield under extreme moisture deficiency. The experiments were carried out in a soil channel and included seven options that differed in terms of cultivation and fertilisation systems. During the experiment, extreme moisture conditions were created by watering only three times during the entire growing season. Soil moisture was also measured systematically in each of the treatments. Analysis of the measurement results showed no significant influence of the moisture content of natural sapropel on the total soil moisture in the experimental treatments. However, an increase in soybean yield of up to 10% was observed in the experimental variants with sapropel. Based on the results of the research, a scheme of a machine for sowing soybeans using Strip-till technology with simultaneous introduction of sapropel with natural moisture content is proposed.