SOIL-MOISTURE DURING VEGETATION OF WINTER-WHEAT IN DEPENDENCE ON SOIL TREATMENTS AND FORECROP

In the potato-growing region at the research station at Nove Mesto na Morave in the years 1989 to 1992 the effect of various soil treatment to winter wheat on the water content in soil was studied. This is a site characterized by 600 m of altitude, annual sum of precipitation of 714 mm, average temperature 6.1-degrees-C. The weather pattern is presented in Fig. 1. Trials were conducted on shallow, acid cambisols. Winter wheat was cultivated after three different forecrops: I - red clover, II - silage maize, III - winter rape. Variants of soil treatments were as follows: A - tillage to 0.20 m (control), B - tillage to 0.10 m, C - sowing into untreated soil, D - horizontal loosening without soil turning (0.15 m). During vegetation in three growth phases of wheat (germination, tillering, shooting) was determined the moisture of soil profile to a depth of 0.30 m, that is in all variants of soil treatments and after all forecrops by the gravimetric method. The results of four-year investigations are summed up in Tab. I. The soil was most moistured in variant A, with traditional soil treatment, during germination of wheat. In view of a forecrop, this was after maize as a forecrop in three of four tested variants of soil treatment. In the phase of tillering the most water had the plants of winter wheat in the variant with direct sowing. Forecrops affected the moisture in the following way: the highest moisture after winter rape in variants A and C, after red clover in variants B and D. During shooting the highest moisture content was again found out in the case of winter wheat sowing into untreated soil. The silage maize was manifested to be the best forecrop in variants A, B and D in view of holding the water for subsequent crop. Highly significant effect of soil treatment on water content in soil in all studied growth phases of winter wheat (Tab. II) is evident from statistical evaluation of data regarding soil moisture.