The formation of the yield by crops is influenced by many factors and the state of the plant itself. The purpose of the study is to determine the efficacy of the preparation Zircon in combination with mineral fertilizers and seed protectant for the formation of spring wheat yield. The research is conducted at the experimental field of the Kazan State Agrarian University in years 2016-2018, with Yoldyz, a regional variety of spring wheat. Seed treatment with growth regulator Zircon increases yield on the background without fertilizers amounts to 0.14 t/ha and 0.21 t/ha without fertilizers and with fertilizers, respectively. Seed treatment with growth regulator Zircon and protectant Dospekh 3 provides the yield increase of 0.18 t/ha without fertilizer additions. When fertilizers are added yield increases by 0.29 t/ha and 0.35 t/ha, for N61P55K55 and N120P126K97, respectively. In this case, return of fertilizers of the grain per 1 kg D. V. makes fertilizers N61P55K55 increase to 7.89 kg, while N120P126K97 amount to 5.57 kg.

The research was carried out in order to study the features of the effect of concentrated organomineral complex liquid fertilizers on the yield and grain quality of spring soft wheat. The work was carried out in 2020-2022 in the Republic of Tatarstan. The scheme of the experiment involved the study of the following options: without presowing seed treatment, herbicide in the tillering phase, insecticide in the booting phase (control); seed treatment with Batr Gum 0.5 l/t, herbicide + Batr Maks 1 l/ha in the tillering phase, insecticide + Batr Maks 1 l/ha in the booting phase; seed treatment with Chudozem 1 l/t, herbicide + Chudozem 2 l/ha in the tillering phase, insecticide + Chudozem 2 l/ha in the booting phase. Varieties Al Varis and Yoldyz were sown at a rate of 6 million viable seeds per 1 ha. Treatment of seeds with preparations Batr Gum and Chudozem increased field germination, and subsequent spraying of vegetative plants with the same preparations increased their safety for harvesting, the length of the stem and ear, the number of oats and grains in the ear. On average, over the years of research, the use of drugs provided an increase in the grain yield of the Al Varis variety at the level of 0.58 ... 0.60 t/ha, of the Yoldyz variety - 0.56 ... 0.58 t/ha. The use of Batr Maks contributed to the formation of spring wheat grains with the highest protein and gluten content in the experiment, as well as vitreousness in both varieties of soft wheat. The most economically profitable was the cultivation of the spring soft wheat variety Al Varis using the preparations Batr Gum and Batr Maks.

The study was carried out in the Republic of Tatarstan (Povolzhsky Federal District of the Russian Federation) in the conditions of grey forest medium loamy soil with weakly acidic reaction of the environment, low humus content, increased and average content of mobile forms of phosphorus and potassium respectively. The soil was intentionally polluted with oil at the rate of 10, 20 and 40 l/m2. Close negative correlation of spring wheat yield from oil dose (R2=0,945...0,997) and positive dependence on the statute of limitations of single soil contamination (R2=0,713...0,993) was established. The possibility of gradual, though slow, natural elimination of phytotoxicity of oil-contaminated grey forest soil without special methods of recultivation is noted. The content of nitrogen, phosphorus and potassium in spring wheat plants under the influence of oil pollution has not changed significantly, but accumulation of carcinogenic substances in them was found. It is indicated that for the objective assessment of detoxification of oil-contaminated soils it is necessary to take into account not only the productivity of plants, but also to study in depth the chemical composition of the crop.

In this study we analyzed the influence of the pre-sowing treatment of spring barley seeds with the biological preparat Rizoagrin and the micronutrient fertilizer Tenso Cocktail against the background of the mineral fertilizer diammofosk on the germination of seeds, the quality of the grain yield and biomass of barley straw, the structure of the crop, the chemical composition of grain and straw under the conditions of the Republic of Tatarstan on gray forest soil. It was found that the use of Rhizoagrin and Tenso Cocktail in combination with diammophos increases the grain yield up to 4.05 t / ha, which is 117 % more than the control. We noted an increase in the productivity of plants, the number of ears, grain per ear and the weight of 1000 grains in relation to the control in the same variant. The fourth option has the highest indicators in terms of nitrogen content in grain and straw – by 5.40 and 8.62% more than in the control. In the second variant, the nitrogen content in the grain is 3.24 % higher than the control, and in the straw – by 5.17 %. In the third variant, the nitrogen content in grain and straw is 2.70 and 6.89 % higher than the control. In terms of the phosphorus content in grain and straw, the increase in the third and fourth variants is at the same level – 3.06 and 5.26 % in relation to the control. The second option does not have an increase in the phosphorus content. There was a decrease in the content of potassium in grain and straw in all variants compared to the control. In the fourth variant, the potassium content in grain is lower than the control by 8.45 %, in straw – by 5.69 %. In the second variant, the potassium content in the grain is lower in comparison with the control by 4.22 %, in the third variant – by 1.40 %. In straw, the potassium content in the second and third variants is reduced by 1.62 %.

This work is dedicated to the evaluation of dependence of grain and leguminous crops yield from the main agrochemical parameters of soil and weather conditions. Proceedings on agrochemical survey of arable soils, crop yields, and the main agro-meteorological indicators of Baltasi municipal district of the Republic of Tatarstan for 1980-2010 years were generalized. Over the years aproductivity of grain and leguminous crops in the region has increased for 1.73-2.25 times, increasing the yield for 37-49 kg per hectare grain per year. The productivity of all crops is most closely connected with the average content of mobile potassium (r = 0.83-0.90) and phosphorus (r = 0.51-0.78). A moderate negative correlation was found between yield of studied species and share of arable land, having an acid reaction (r = - 0.32-0.48). During the study period the moisture content of the Baltasi municipal district of Tatarstan often (recurrence is 63.4%) was characterized as insufficient or arid. We found a negative correlation of spring crops productivity (spring wheat, barley, pea) from the amount of active temperatures, which indicates that heat supply of the area is not a limiting factor for these crops, and a growing fever of the season often has a negative impact. The tightness and direction of the correlation the productivity of spring crops and peas from the amount of rainfall is changing dramatically by periods: if the amount of precipitation in May has a very weak positive effect on the productivity (r = 0.16-0.17), the rain, falling during maturation and harvesting, have a negative impact (r = -0.14 and -0.21). The largest positive impact on the spring crops yield had a rainfall of June. Especially the correlation was noticeable for pea (r = 0.64) and spring wheat (r = 0.58). Compared with the June precipitation, total precipitation during the growing season had on the yield of spring crops significantly less impact (r = 0.32-0.53). The productivity of spring crops was less dependent on the amount of annual rainfall (r = 0.28-0.49). The productivity of spring crops and peas are most closely correlated with Selyaninov hydrothermal coefficient in June (r = 0.50-0.65), and winter rye - in August before sowing (r = 0.45). Therefore, to predict the effects of the prevailing weather conditions on productivity of certain crops, it should be used the hydrothermal coefficient of Selyaninov of the relevant month. According to the yield correlation coefficients from Selyaninov hydrothermal coefficient on vulnerability to adverse weather conditions (insufficient moisture content, high temperature) experienced species can be arranged in the next growing rate: peas <spring wheat <barley <winter rye.