About Irrigation Mode

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

When irrigating any plants, it is important to correctly establish the irrigation regime and choose the most rational method and technique for irrigation. Irrigation regime (timing, quantity and rate of irrigation) is usually provided for in projects for the construction of irrigation systems. The power of the water-lifting equipment, the size of the irrigation canals, pipelines and, ultimately, the efficiency of irrigation depend on it

For trees of various fruit species and varieties, the irrigation regime is not the same. So, the autumn-winter varieties of pome breeds absorb more water than summer ones, therefore, the most valuable varieties of the latest ripening periods are placed on irrigated lands.

The age of the planting also matters. According to the data of the experimental-reclamation station, the consumption of water by an apple tree of the Parmen winter gold variety (with the soil kept under black fallow) at different ages during the growing season was: from 11 to 15 years - 3600 cubic meters. m, from 16 to 20 years - 4200, from 21 to 25 -5600 and from 25 to 30 years - 6000 cubic meters. m per 1 ha.

Water consumption changes with different soil content in the garden. For example, when the soil was covered with perennial grasses (alfalfa with multi-cut ryegrass), more water was consumed - up to 7000 - 8000 cubic meters. m, which is almost equal to the maximum possible evaporation over the same period.

When establishing an irrigation regime, as a rule, they strive to ensure optimal moisture content in the active soil layer during the entire growing season. The size of this layer depends on the soil and the characteristics of the placement of the root system, but on average it is within 0.8-1 m.

In areas of insufficient and unstable natural moisture, the irrigation regime cannot be constant, established in advance. Therefore, sometimes recommended schemes, where the timing of irrigation is confined to certain phases of tree development, can serve as a guide only when drawing up plans for the use of water from irrigation systems, when developing technological maps. In practice, the number of irrigations and the timing of their implementation change annually in accordance with meteorological conditions (evaporation, amount and time of precipitation).

In gardens where the soil is covered with perennial grasses, the irrigation rate is 1800-2000 and 5400-5600 cubic meters. m of water per hectare. The need for the first watering occurs at different times (May, June, July). In this regard, the most reliable indicator of the time of the next irrigation is soil moisture.

Different authors recommend different moisture levels for watering. However, there is no contradiction here, because this is due to the different soil conditions in which he carried out the experiments. Basically, there is consistent data: the permissible decrease in moisture content in the active layer is 80-75% of the maximum field moisture capacity (PPV) on heavy soils, 75-70% on soils of medium texture and 60-55% on light soils. At the same time, soil moisture is mobile and easily accessible to plants.

It should be borne in mind that sometimes, for example, in the ripening phase of fruits, a slight decrease in moisture is permissible. During this period, trees consume less water, and a moderate supply of it, which helps to improve the quality of fruits, is satisfied with easily accessible moisture, which is available deeper than the active layer. Some variation of the lower limit of the optimal soil moisture is possible due to the different species and varietal compositions of the garden. In large plantations, it is usually watered for several days, which depends on the bandwidth of the channels, the organization of work, and labor productivity. Therefore, it is impossible to water the entire garden area within the precinct distribution channel or pipeline, maintaining the pre-irrigation level of humidity established for these conditions, because during the time from the first to the last day of irrigation in this area, the soil moisture decreases.