Effect of alfalfa stand on runoff and erosion manifestations mentioned
on sloping locations was studied in a system of Six elementary model
basins. Inclination (slope gradient) of individual pairs of basins amo
unted to 3, 8 and 12%. Rainfall surface runoff and erosion soil washin
g were classified in Tab. II and characterized mathematically as funct
ional dependence of growth height (three variants: a - stubble, b - 4
to 25 cm, c - 26 to 60 cm) and rain intensity (F-D) calculated from da
ta mentioned in Tab. I. Functional dependence of runoff coefficient (p
hi) on rain intensity can be expressed as follows: a) phi = 0.10 F-D -
0.06; b) phi = 0.07 F-D - 0.08; c) phi - 0.05 F-D - 0.08; calculated
values related to erosion soil washing (m(e)) are expressed analogical
ly: a) m(e) = 11.67 (F-D - 1); b) m(e) = 1.33 (F-D - 1); c) m(e) = 0.5
6 (F-D - 1). Results of the study demonstrated significant positive hy
drological role of alfalfa. Erosion washing on grown alfalfa locations
was as much as 250 times smaller and on alfalfa stubbles as much as 2
7 times smaller as compared to unsown locations.