Effects of Previous Cultivation of Sugarbeet on the Subsequent Cultivation of Cotton
Aug 3, 2018
The effect of previous cultivation of sugarbeet, legume, cotton and corn on the subsequent crops of cotton and corn was studied in a two - year rotation cycle at two Greek locations in 1994 and 1995. This paper only discusses the two cultivation systems, 1) sugarbeet - cotton and 2) cotton - cotton. The effect of sugarbeet in cotton cultivation is considered negative based on various field observations and the personal experience of farmers. Some of the supposed causes of this effect are evaluated. Growth analysis in cotton grown after sugarbeet showed that plants had a significant delay in appearance of squares, flowers and bolls, delayed weight development of vegetative and reproductive parts, delayed Leaf Area development and reduced chlorophyll, compared to cotton grown after cotton. This difference gradually declined or disappeared during plant life cycle. Thus although cotton grown after sugarbeet yielded less in the first picking, total yield was not inferior. Soil analytical data during the second year were not found to be influenced by the previous cultivation. Heavy rainfall in October 1994 and spring 1995 possibly leached residual N and balanced the differences between crops. In addition, no sugarbeet residues were left in the soil and it was hand harvested, possibly explaining the lack of effect on the C/N ratio and soil mycoflora. The increased soil compaction observed in plots planted to sugarbeet, combined with delayed cotton growth, support the hypothesis that the swollen sugarbeet roots increase soil compaction, prohibiting root penetration of the following cotton crop.