EFFECTS OF REPEATED CROPS IRRIGATED WITH LOW-MINERALIZED DRAINAGE WATER, FERTILIZER RATES, AND BIOPREPARATIONS ON VOLUMETRIC MASS OF SOIL

Аннотация

In this article, information is provided about millet and sunflower plants, which were irrigated with low-mineralized drainage water 2 times a season as an additional water source. The plants were treated with Nanosilicon and AMINOSID Universal Si biopreparations. The fertilization procedure for millet was N-50, P-105, K-75 kg ha-1, while for sunflower, it was N-200, P-140, K- 100 kg ha-1. The article also discusses changes in the volumetric mass of soil under conditions of water shortage in the experimental field. Keywords: soil, repeated crop, millet, sunflower, drainage water, Нанокремний, AMINOSID Universal Si, biopreparation, volumetric mass of soil. Introduction. One of the main factors determining soil fertility in the cultivation of agricultural crops is its water-physical properties. Key properties such as soil density, volumetric and specific mass, total porosity, water permeability, and water-holding capacity are of great agronomic importance. These indicators influence the soil's air, heat, nutrient, and water regimes, as well as the activity of microorganisms and the growth and development of plants. They are also crucial in determining crop irrigation procedures[6]. The water-physical properties of soil vary depending on the soil type, mechanical composition, structure, and levels of organic and mineral substances, as well as cultivation and tillage practices. Meadow-alluvial soils are considered to have naturally favorable water-physical properties. Moreover, scientific and practical studies have proven that when these properties are optimally managed, plants exhibit good growth and development, leading to high yields [7]. The water-physical properties of soil are constantly changing due to activities such as soil cultivation, irrigation, fertilization, salt leaching, crop rotation, and other agricultural practices. It is essential to continuously monitor the state of these properties, especially in irrigated agriculture. The main water- physical properties of soil, including bulk mass, porosity, water permeability, field capacity, and capillary rise, are measured in experimental areas [2]. Research materials and method. Field experiments were conducted in the meadow of the Agrofayz Ziynati farm in the Vobkent district of the Bukhara 186 ACADEMIC RESEARCH IN MODERN SCIENCE International scientific-online conference region, under conditions of alluvial soil with medium salinity and medium loam texture. The water level was 2.0-2.5 meters, and the mineralization was 2.5-3.0 g/l. Pre-cultivation irrigation was carried out to promote the germination of the repeated crops. In the experimental field, millet seeds were sown with 30 cm between rows and sunflower seeds with 60 cm between rows, at a depth of 4-5 cm using a seeder [5]. The experimental plots were arranged on a single level in 3 rows, with each plot covering an area of 240 m² (50 m in length and 4.8 m in width). The total area of the experimental field was 1440 m², with a total field area of 4320 m². In the experiment, after harvesting the winter wheat crop, millet “Saratovskoe-853” and sunflower “Dilbar” were grown as repeated crops. Experimental plots 1-4 were irrigated with drainage water as a control. In plots 2-5, the crops were treated with a Nanosilicon biopreparation before irrigation, and in plots 3-6, the crops were treated with AMINOSID Universal Si biopreparation before irrigation. The millet (Panicum miliaceum L. “Saratovskoe-853”) and sunflower (Helianthus annus L. “Dilbar”) crops were irrigated with low-mineralized drainage water (3 g/l). The millet crop was irrigated when soil moisture was at 70-75-65% relative to limited soil moisture capacity, while the sunflower crop was irrigated twice in the 0-1-1 irrigation system when soil moisture was at 70- 70-65% relative to LFMC. The soil moisture calculation layer before irrigation was 50-70-50 cm for both crops. Seasonal irrigation norms were 1752-1451 m3 ha-1 for millet and 1755-1464 m3 ha-1 for sunflower. Fertilization for the repeated millet crop was applied at the rate of N-50, P- 105, K-75 kg ha-1, and for the sunflower crop at the rate of N-200, P-140, K-100 kg ha-1. Before planting, the seeds were treated with biopreparations: Nanosilicon at 300 g t-1 and AMINOSID Universal Si at 0.8-1.0 l t-1. During the growing season, before the first and second irrigations, the crops were further treated with Nanosilicon at 100 g ha-1 and AMINOSID Universal Si at 5.0 l ha-1. These biopreparations were used effectively. Observations, calculations, and analyses in the field experiment were conducted according to the methodological manual of UzPITI, “Methods of Conducting Field Experiments” [3]. The “Brief Methodological Guidelines for the State Testing of Growth Regulators” were followed during the application of chemical substances[1]. The obtained data were subjected to mathematical statistical processing using the method of B.A. Dospekhov [4]. 187 ACADEMIC RESEARCH IN MODERN SCIENC