Influence of mulching trunk strips in intensive apple orchads on the productivity and efficiency of irrigation water
On the basis of extensive researches, the particular weather conditions, mode of irrigation, yield intensive planting of apple variety Jonagold on rootstock M9 (Planting figure 4 × 1 m) in the zone of unstable wetting on ashed low humus hard clay loam black soil the irrigation rate is determined under different systems of keeping the soil in the garden and irrigation regimes. It was established that in all the years of research there was an uneven distribution of rainfall during the growing season, which is the reason of dry periods, even in wet, according to the supply of rainfall, vegetation periods. Therefore, the rainfall provision of the growing season cannot objectively describe the degree of moisture for an apple tree. Mulching trunk stripes in conditions of natural providing soil moisture, compared to a steam system of keeping garden significantly increased the yield in the presence of droughts in wet and dry, as for supply of rainfall, vegetation periods. Comparison of irrigation variants in conditions of different systems of keeping garden soil showed that mulching trunk stripes in combination with irrigation and before irrigated threshold of soil moisture 80% НВ or mixed mode of irrigation (80/70% НВ) significantly increases the yield during the dry periods of summer. However, this agrotechnical measure provides an opportunity to save on average in conditions of before irrigated soil moisture level 80% НВ 52%, and in conditions of variable irrigation regime (80/70% НВ) - 57% of irrigation water. With the combined application of mulching and irrigation the most optimal mode is the irrigation one with maintaining moisture 0-40 cm soil not less than 80% of HB during flowering, formation, growth of fruits and initial shoot growth and not less than 70% of HB in the second half of the growing season. Using irrigation water by an apple tree to obtain a unit of additional production under such conditions is most effective. With the limited resources of water a significant increase in yield is provided by a combined use of mulching and irrigation with maintaining moisture 0-40 cm soil not less than 70% of HB during the growing season. The role of irrigation in the yield formation of an apple tree is dominant and is 71-73%. Effect of mulching in wet and dry, according to the supply of rainfall, vegetation periods is 8.10%, falling in very dry periods to 2%.