Improvement of the subsoil irrigation system
Our three-year research with table beet and four- year research with radish showed, that the subirrigation regimes with the Soil Pre-Irrigation Moisture (SPIM) 75, 75-85-75, 85 % of Full Moisture Capacity (FMC) and with the application of calculated doses of mineral fertilizers make it possible to obtain the planned yield up to 80 tons per hectare of roots in the light brown soils of the Lower Volga region. The experiments with table beets showed that for yield and productivity of use of moisture for the formation of 1 ton of production, subsoil irrigation is just as effective as drip irrigation. However, in comparison with sprinkling, this method of irrigation allows to obtain an increase in yield up to 9.6 t / ha or up to 14.0%, simultaneously reducing the water consumption coefficients and irrigation water consumption by 22.0 and 27.9%, respectively. Our research with table beets on the site of subsoil irrigation with distances between subsoil humidifiers of 1.2; 1,5 and 1,8 m and then - with a radish on a site with distances 1,2; 1,4 and 1,6 m allowed to establish that it is possible, without reducing the efficiency of irrigation, to increase the this distance from 1.2 to 1.4 m. This contributes to a total reduction in the cost of the entire subsoil irrigation system by 13% per hectare. Economic calculations showed that systems of subirrigation, having an initial cost of 3... 5 times greater than drip irrigation systems, can quickly pay off in the first years of operation, without requiring, in contrast to these systems, no additional costs in the future.