Efficiency of different sources of organic matter in maintaining fertility level of chernozem soil
1986
Stevanovic, M. | Zeravica, M. (Poljoprivredni fakultet, Novi Sad (Yugoslavia))
Several years of plowing under harvest residues caused a slight decrease in soil pH, an increase in readily available P and K and an increase in the humic content of soil. The portion of total nitrogen was increased only by long term manuring with mineral fertilizers. The use of harvest residues together with mineral fertilizers changed the C/N ratio of the soil. The change in the C/N ratio intensified the mineralization of nitrogen. Maize yields were lower in the four-crop rotation than in the two or five-crop rotations. The presence of alfalfa in crop rotation reduced the need for fertilization. The experiment was conducted on a two-crop rotation: wheat-maize; four-crop rotation: wheat-sugar beets-maize-sunflowers; five-crop rotation: wheat-sugarbeets -alfalfa-maize-sunflowers.
显示更多 [+] 显示较少 [-]