Abstract
It is known that the average wheat yield in Kazakhstan varies between 11–14 kg/ha (instead of a potential 40–45 kg/ha) and the main reasons for crop shortages are soil depletion and compaction, and the low efficiency of mineral fertilizers. To loosen the soil and ensure optimal plant nutrition, deep loosening and extensive application of mineral fertilizers are necessary. The research purpose is to increase crop productivity by developing a technical tool for deep loosening of the soil with simultaneous differentiated and tiered application of mineral fertilizers in a precision farming system. Taking into account the soil and climatic conditions of Northern and Central Kazakhstan, and based on the results of theoretical and experimental studies, a chisel-type subsoiler with fertilizer application has been developed. The implement performs deep soil loosening with the simultaneous differentiated application of two types of fertilizers at three depths: 8–10 cm (3), 16–18 cm (2), and 23–25 cm (1). Depths (1) and (2) can be adjusted jointly, while depth (3) is regulated independently, regardless of the overall tillage depth. The results of laboratory and field trials demonstrated that the total load capacity of the fertilizer applicator ranges from 2,430 to 2,700 kg, with a throughput capacity between 0.032 and 0.274 kg/s. The range of differentiated application rates varies from 0 to 495 kg/ha. The application rate variability was 3.1%, while the transverse distribution non-uniformity ranged from 3.5% to 4.1%.