Author(s) |
Усик С. В., , , Eshchenko V.O., Doctor of Agricultural Sciences, Professor, Head of Department of General Agriculture, Uman National University of Horticulture, Ukraine Карнаух О. Б. , , , |
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Category | The Agronomy | ||
year | 2020 | issue | Issue number 96. Part 1 |
pages | 432-443 | index UDK | 631.582:631.434 | DOI | 10.31395/2415-8240-2020-96-1-432-443 (Link) |
Abstract | The results of the research on the determination of short-term crop rotations’ influence with different saturation of fodder-grain crops (soybeans, barley, maize) in combination with the cultivation of the main industrial crop in the beet sowing area with sugar beets on the bulk density and agronomically valuable structure of chernozem in the soil layer of 0–30 cm. Saturation of crop rotations with maize had little effect on soil density in the field of sugar beets in the middle of their growing season. In 2014, the soil density in the layer of 0–10 cm was the same (1,18 g/cm3) in crop rotation № 9 and 17, which have 20 and 100 % of tilled crops, respectively. It was 0,02 g/cm3 smaller and also the same in the variants 15 and 16 having 60 and 80 % of tilled crops. In the 10–20 cm layer, the difference between the variants was also not related to the change in the structure of sown areas. At a depth of 20–30 cm, the bulk density of soil tends to increase, but there is no difference between the variants, as it was in the upper layers. The same value (1,27 g/cm3) this year was recorded in the variants № 9 and 17, which have 20 and 100 % of tilled crops respectively. And as a summary: the average values in the layer of 0–30 cm differ only by 0,01 g/cm3. There were no natural changes in the bulk density of soil in 2015. In the soil layer of 0–10 cm the extreme values of this index (1,19 and 1,22 g/cm3) were obtained in variants with 80 and 100% of tilled crops. And in the lower layer (10–20 cm) it was typical for the variants № 15 and 17, with 60 and 100% of tilled crops. The soil layer of 20–30 cm this year was characterized by the highest value of density which reached 1,30 g/cm3 and was the same in the variants № 9, 15 and 17, which due to corn contained 20, 60 and 100% of tilled crops, respectively. A similar absence of regular changes in the physical condition of the soil was observed in the 0–30 cm layer. The structural condition of the soil in the arable layer, during the period of leaf closure in the row spacing of sugar beets changed regardless of the share of crops in the structure of sown areas. In 2014, in crop rotation № 9 in general, in the absence of maize in the soil layer 0–10 cm, 73,8 % of agronomically valuable units were observed. When expanding the plantings of this crop due to soybeans and barley in the variant № 15, the increase in soil aggregates is 1,3 %. Whereas with a further increase in maize to three fields (variant № 17) only 0,6 %. The same is noted in layers of 10–20 and 20–30. Therefore, as a result, the average values of the variants in the layer of 0–30 cm are almost the same. In 2015, the same phenomenon was noted and therefore it does not require in-depth analysis of individual layers of soil, and it is enough to stop at the average layer of 0–30 cm. In this variant the same index was recorded in the crop rotation № 9 with the 20 % share of tilled crops and in the crop rotation Nr 17 with the 100 % share of tilled crops. Taking into account the relatively low value of the variation coefficient in each variant during both years of research, it is safe to say that the density and structural condition of the soil in the arable layer for the period of leaf closure in the row spacing of sugar beets is in no way related to the saturation of crop rotations with the tilled crops. | ||
Key words | short-term crop rotations, agrophysical indices, soil density, agronomically valuable structure, soybeans, barley, maize, sugar beets |