Mechanized Placement of Drip Tape in Potato Comb

Over the past two years, decrease in potato yield has been observed in the Moscow region. One of the main reasons is unfavorable weather conditions. To obtain a guaranteed yield, as well as to improve the quality of products, it is necessary to carry out reclamation works, including additional irrigation. Creation of the optimal water - air balance of the plant throughout the entire growing season will increase productivity, and improve the quality of agricultural products. Drip irrigation is the most economical method of irrigation, but its widespread use is hindered by the high proportion of manual labor when installing the drip tape. A mechanized method of laying the drip tape by placing the working equipment on the Grimme GF-75/4 comb former is offered. The existing methods for determining the irrigation rate do not consider the parameters of the humidification circuit, which leads to excessive irrigation and additional losses of irrigation water. The paper offers a method for determining the irrigation rate considering the shape of the humidification circuit and its geometric parameters.

Effect of Water Irrigation Amounts and Nitrogen Fertilizer Levels on Teosinte Productivity and Optimal Economic N-Rates Under Salinity Stress

The teosinte plant is one of the most important fodder crops that is affected by drought and nitrogen supply, and therefore the optimal supply of N- fertilization may be affected by the amount of irrigation water added to teosinte plants to obtain an economic crop. Two field experiments were done to study the effect of irrigation amount at three levels (100%, 80% and 120%) and nitrogen fertilizer levels (60, 90 and 120 kg N fed-1) (Feddan = 4200 m2) on the yield productivity of teosinte and determined the optimal and economic optimal N rate as affected by irrigation amount levels, and water relations. The results showed that the highest values of the fresh and dry weight of cuts, as well as plant height and stem diameter, were obtained when applying the full irrigation rate with full irrigation and 120 kg N fed-1. The results also showed that a 20% decrease in the irrigation rate led to a deterioration in the values of those parameters. Although the results showed that the full irrigation amount more saved water at two seasons under various levels of nitrogen. Moreover, all water relationships gave the best mean values for actual evapotranspiration, water utilization and use efficiencies also, higher application efficiency values at full irrigation and 120 kg N-levels than the other treatments. Also, the results showed that the economical yield of teosinte fresh cuts when using 211.01 kg N fed-1 with 120% of the recommended irrigation rate was higher when using 148.22 kg N fed-1 with the recommended irrigation rate. Therefore, we recommend using 211.01 kg N fed-1 to get an optimum economic yield of teosinte fresh cuts, especially in saline soil, with 120% of the recommended irrigation rate.

Irrigation regime and fertilization rates for vegetable corn varieties in the Samarkand region

Цель исследований – изучить рост, развитие и урожайность сортов сахарной (овощной) кукурузы Шерзод и Замон при различных режимах орошения и нормах удобрений и установить оптимальные параметры режима орошения и нормы удобрений, обеспечивающих получение устойчивого высокого урожая (не менее 8,5–9,0 т/га). Исследования проведены в 2017–2020 годах на орошаемых лугово-сероземных почвах Самаркандской научно-опытной станции Научно-исследовательского института овощебахчевых культур и картофеля. Почвы – среднесуглинистые с залеганием грунтовых вод на глубину 4–5 м. В опытах изучали два режима орошения по предполивной влажности почвы не ниже 65–70 и 70–80% ППВ. В каждом режиме орошения изучали следующие нормы удобрений: 1. N150P120K75, 2. N200P160K100, 3. 30 т/га навоза + N150P120K75, 4. 30 т/га навоза + N200P160K100 кг/га. При режиме орошения по предполивной влажности почвы не ниже 65–70% ППВ проводили шесть поливов по схеме 2–4 с интервалом 18–16–14–12–10–10 дней. Оросительная норма – 5696–5734 м3/га, при этом поливная норма – 827–1185 м3/га. При режиме орошения по предполивной влажности почвы не ниже 70–80% ППВ растения поливали восемь раз по схеме 3–5, то есть в фазах всходов – образования метелки – три раза, а в фазах образования метелки – полной спелости – пять раз, через каждые 15–13–10–9–8–7–7–9 дней с оросительной нормой 5451–5500 м3/га, при поливной норме 536–918 м3/га. Высокий и гарантированный урожай сортов сахарной (овощной) кукурузы Шерзод и Замон (8,6–10 т/га) можно получить при выращивании их при режиме орошения по предполивной влажности почвы не ниже 70–80% ППВ или при 8 поливах по схеме 3–5, то есть в период фазы всходов – образования метелки – 3 поливов, а во второй период в фазах образования метелки – полной спелости – 5 поливов с поливной нормой 536–918 м3/га и совместном внесении органоминеральных удобрений в норме 30 т/га навоза + N200P160K100 кг/га. The purpose of the research is to study the growth, development and yield of varieties of sugar (vegetable) corn Sherzod and Zamon under various irrigation regimes and fertilizer rates and to establish the optimal parameters of the irrigation regime and fertilizer rates that ensure a stable high yield (at least 8.5–9.0 t/ha). The research was carried out in 2017–2020 on irrigated meadow-gray-earth soils of the Samarkand Science and Research Station of Scientific Research Institute of Vegetables Crops, Melons and Potatoes. The soils are medium loamy with the occurrence of groundwater to a depth of 4–5 m. In the experiments, two irrigation modes were studied for pre-irrigation soil moisture not lower than 65–70 and 70–80% PPV. In each irrigation regime, the following fertilizer standards were studied: 1. N150P120K75, 2. N200P160K100, 3. 30 t/ha of manure + N150P120K75, 4. 30 t/ha of manure + N200P160K100 kg/ha. Under the irrigation regime, according to the pre-irrigation soil moisture not lower than 65–70% of the PISM, six irrigations were carried out according to the 2–4 scheme with an interval of 18–16–14–12–10–10 days. The irrigation rate is 5696–5734 m3/ha, while the irrigation rate is 827–1185 m3/ha. Under the irrigation regime for pre-irrigation soil moisture not lower than 70–80% PISM, the plants were watered eight times according to the scheme 3–5, that is, in the phases of germination – panicle formation – three times, and in the phases of panicle formation – full ripeness – five times every 15–13–10–9–8–7–7–9 days with an irrigation norm of 5451–5500 m3/ha, with an irrigation norm of 536–918 m3/ha. A high and guaranteed yield of varieties of sugar (vegetable) corn Sherzod and Zamon (8,6–10 t/ha) can be obtained when growing them under the irrigation regime for pre – irrigation soil moisture not lower than 70–80% PISM or with 8 watering according to the scheme 3–5, that is, during the germination phase – the formation of a panicle –3 watering, and in the second period in the phases of the formation of a panicle – full ripeness – 5 watering with a watering norm of 536–918 m3/ha and joint application organomineral fertilizers in the norm of 30 t/ha of manure + N200P160K100kg/ha.

Effects of Different Irrigation Management Practices on Potato (Solanum tuberosum L.)

Decisions in irrigation management can greatly impact the overall sustainability of potato production. A field study was conducted in 2018 and 2019 to evaluate the impacts of different irrigation regimes on yield and quality of three russet potato varieties. For Russet Burbank, fry quality at harvest and at 4 and 8 months after harvest was assessed. During early growth stages, the standard practice of irrigating to maintain 60–80% soil moisture was employed. The irrigation treatments were applied during the late tuber bulking and maturation growth stages, and consisted of irrigation at 125%, 100%, 75%, and 50% of daily evapotranspiration (ET). We found that 125%ET provided no increase in total yield and marketable yield compared to other treatments in 2018, and it produced similar marketable yield to 100%ET in 2019. Total yield, but not marketable yield, of 125%ET and 100%ET was significantly higher than the number under 50%ET in 2019. In both years, increasing irrigation rate led to a decrease in irrigation efficiency and water-use efficiency. Irrigation rate had no significant effects on tuber quality at harvest and during storage. This study indicated that over-irrigation at 125%ET was not beneficial to profitable potato production in the Upper Midwest of the US, and deficit irrigation at 75%ET during late tuber bulking and tuber maturation could potentially result in more sustainable water use while not jeopardizing tuber growth. The results support the possibility of adopting late-season deficit irrigation for growing potatoes in the region, though more years of research would allow for a better understanding of the impacts of this practice.

Soil-hydrophysical information support of precise irrigation farming

The relevance of the study is determined by the demand for a physically adequate mathematical description of the interactions of water in the soil to develop a model of soil moisture dynamics as the intellectual core of resource-saving technologies for precise irrigation farming. The aim of the work is theoretical substantiation and mathematical formulation of the hydrophysical functions of the soil, taking into account hysteresis. A description of three systems of soil hydrophysical functions is given. To verify and compare the systems, computational experiments were carried out using both the package of original software and “3305 Ida silt loam (> 15 cm)” soil data from the authoritative literary source – the Mualem catalogue. The parameters of the functions were identified by the method of point approximation of the experimental data on the main branches of the hysteretic water-retention capacity. Using these parameters, we calculated (i) predictive estimates for the values of the function of relative hydraulic conductivity; (ii) scanning branches of the hysteretic water-retention capacity; (iii) precise irrigation rate. The hysteresis phenomenon is not typical for the hydraulic conductivity as a function of the volumetric water content in the soil. The original functions of System 3 are recommended for use. The advantages of the proposed method for calculating the precise irrigation rate are shown. The benefit of each system is that the functions forming this system, namely the water-retention capacity and the relative hydraulic conductivity of the soil, have a common set of parameters. For the type of soil considered, in case of using the identical value of pre-irrigation soil moisture (179 [cm3 · cm-3]), both for calculating the precision irrigation rate and according to the “traditional” method, when moistening 50 cm soil layer, the total unproductive water consumption at irrigation rate 555 [m3 · ha-1] can reach 0.029 [cm3 · cm-3] or 140 [m3 · ha-1] in the calculated layer. At the same time, when applying precision standards, an excess of free moisture is not formed. It shows additional opportunities not only to save water during irrigation, especially in arid regions, but also to reduce the leaching of nutrients and agrochemicals outside the calculated soil layer and, accordingly, to reduce the additional environmental load on the surrounding area.

Effect of irrigation rate on Sudan grass yield, grown as a second crop

The aim of the present study was to establish the effect of irrigation rate on the yield of Sudan grass variety Engje-1, grown as a second crop for silage on meadow-cinnamon soil for the region of Southern Bulgaria. For this purpose, an experiment with Sudan grass variety Endje-1 on the experimental field of the Agricultural Institute – Stara Zagora, after its predecessor barley, was conducted. The Sudan grass was harvested in the brooming stage. Five variants were explored: Variant 1 – without irrigation (control); Variant 2 – with optimal irrigation, 75-80% of field capacity (FC); Variant 3 – irrigation as Var.2 but with removal of the first watering; Variant 4 – irrigation as Var.2 but with removal of the second watering; Variant 5 – irrigation as Var.2, but with removal of the third watering. It was found that the efficiency of 1m3 of irrigation water was the highest at the optimum variant (Var.2), where 5.36 kg of dry mass (DM) were produced by 1 m3 of water. With the removal of the second irrigation (Var.4), the yield on the dry mass decreased by 6.4% compared to the optimal variant (Var.2), and with the removal of the first irrigation (Var.3) the losses on the dry mass reached, 12.3%, respectively. The highest values of this indicator were obtained by varying the second irigation (Vаr.4) – 7.53 kgDM/m3 water. The coefficient of efficiency of the irrigation rate, representing the ratio between the increase of the yield (in comparison with the version without irrigation – Vаr.1), and the size of the realized irrigation norm had the highest value in the version without second irrigation (Vаr.4) and the lowest values for the version without first irrigation (Vаr.3).

Irrigation Recommendation for Water Saving and Salinity Control in Horticulture in the Semi-arid Lower Cheliff Plain (Algeria)

Salinity and water deficit are two major issues for agricultural development in Algeria. The Lower Cheliff plain, northwestern Algeria, is, furthermore, characterised by semi-arid Mediterranean climate, and soils with high clay content. Our study area was a 4 ha farm located in Oued Rhiou and another 1 ha farm located in Ouarizane, both upstream in the Lower Cheliff plain, and irrigated with waters of different salinities: 1.8 and 5.5 dS m-1, respectively. The plots were equipped with drip irrigation and subsurface drainage systems. Farmer’s irrigation management of artichoke and melon were observed during the respective cropping seasons from September 2010 till June 2011, and from April till July 2011. The total irrigation amounts were, respectively, 364 mm and 240 mm, while the precipitations were 367 mm and 67 mm. The soil properties were determined in the entire rooting depths down to 80 cm for artichoke and 60 cm for melon. In addition to these, irrigation water composition, and crop development parameters were used to simulate soil salinity using the SALTIRSOIL_M model. Simulations and observations of soil pH, main ion concentrations and ECe showed reasonable agreements for June 2011. Next, the irrigation schedules that would have met the water needs of both crops, while simultaneously keeping soil salinity below harmful levels were estimated using the model. For the artichoke plot, a lower irrigation rate (290 mm yr-1) could have kept water deficit and soil salinity below their respective harmful thresholds. For the melon plot, on the contrary, a higher irrigation rate (480 mm yr-1) is able to neutralise the water deficit, though not completely the salinity stress would have been adequate. Farmers’ irrigation practices in the context of the climate, water quality and soil properties of the Lower Cheliff plain can be analysed and improved with the aid of soil salinity modelling.