The effect of alfalfa age on the accumulation of total and soil organic matter when rotating grain crops

Исследования проведены в 2013–2015 годах в ООО «Вымпел 2002» в Хасавюртовском районе Республики Дагестан. Почва экспериментального участка содержит в пахотном слое гумуса 2,77%, Р2О5 — 2,21 мг, К2О — 32,8 мг/100 г почвы, плотность в пахотном слое — 1,24 г/см3, наименьшая влагоёмкость слоя 0–0,6 м — 29,2%. Целью наших исследований являлось выявление влияния возраста люцерны на накопление общей и неотчуждаемой из почвы органической массы в зернокормовом севообороте в условиях Западного Прикаспия. Рассмотрено два севооборота (с двухлетней и трёхлетней люцерной), по пласту и обороту пласта выращивали озимую пшеницу, после уборки которой в пожнивный период с помощью провокационного полива формировали пожнивный естественней фитоценоз (ПЕФ). Степень насыщения севооборотов люцерной составляла соответственно 50 и 60,0%, озимой пшеницей + ПЕФ — 60,0 и 40%. Установлено, что увеличение срока использования люцерны в зернотравяных севооборотах с 2 до 3 лет и доли её в структуре посевных площадей с 50 до 60% способствовало увеличению сборов сена с 1 га севооборотной площади на 2,57 т/га (на 19,0%), зерна озимой пшеницы по пласту — на 7,9%, по обороту пласта — на 6,5%, надземной массы ПЕФ — на 5,3 и 5,1% соответственно. Одновременно увеличивалось и количество накапливаемой растительной массы с 71,56 до 92,66 т/га севооборотной площади. Но в том случае, когда люцерна в севообороте использовалась 2 года, а доля озимой пшеницы с последующим использованием пожнивного периода под ПЕФ увеличивалась с 40 до 50% севооборотной площади, неотчуждаемой из почвы растительной массы накапливалось больше на 20,2%. Заслуживает уточнения в методическом плане вопрос об отнесении части урожая сена люцерны, произведённого в хозяйстве, к неотчуждаемой из почвы продукции подобно тому, как это делается в отношении соломы, только 60% которой считается экосистемной. The investigation took place at the OOO “Vympel 2002” in the Khasavyurt district of the Republic of Dagestan in 2013–2015. Soil of the trial field contained 2.77% of humus, Р2О5 — 2.21 mg, К2О — 32.8 mg/100 g of soil, layer density — 1.24 g/cm3, the lowest moisture content of the 0–0.6 m layer — 29.2%. The aim was to test the effect of alfalfa age on the accumulation of total and soil organic mass in grain crop rotation in the Western Caspian region. Two crop rotations were studied (two- and three-year old alfalfa). After harvesting winter wheat the plot was irrigated to form post-harvest natural phytocenosis. Alfalfa proportion amounted to 50 and 60%, winter wheat + post-harvest natural phytocenosis — 60 and 40%. Cultivation of alfalfa for 3 years instead of 2 and increase in its proportion from 50 to 60% improved hay yield by 2.57 t ha-1 (19%), wheat grain yield — by 7.9 and 6.5%, top mass of post-harvest natural phytocenosis — by 5.3 and 5.1%, respectively. Plant mass increased from 71.56 to 92.66 t ha-1. When alfalfa was cultivated for 2 years and winter wheat proportion raised from 40 to 50%, accumulation of soil organic matter improved by 20.2%. Attributing part of alfalfa hay to soil organic matter was performed the same way as for straw, only 60% of which belonged to an ecosystem.

Deciphering the microbial and molecular responses of geographically diverse Setaria accessions grown in a nutrient-poor soil

The microbial and molecular characterization of the ectorhizosphere is an important step towards developing a more complete understanding of how the cultivation of biofuel crops can be undertaken in nutrient poor environments. The ectorhizosphere of Setaria is of particular interest because the plant component of this plant-microbe system is an important agricultural grain crop and a model for biofuel grasses. Importantly, Setaria lends itself to high throughput molecular studies. As such, we have identified important intra- and interspecific microbial and molecular differences in the ectorhizospheres of three geographically distant Setaria italica accessions and their wild ancestor S. viridis. All were grown in a nutrient-poor soil with and without nutrient addition. To assess the contrasting impact of nutrient deficiency observed for two S. italica accessions, we quantitatively evaluated differences in soil organic matter, microbial community, and metabolite profiles. Together, these measurements suggest that rhizosphere priming differs with Setaria accession, which comes from alterations in microbial community abundances, specifically Actinobacteria and Proteobacteria populations. When globally comparing the metabolomic response of Setaria to nutrient addition, plants produced distinctly different metabolic profiles in the leaves and roots. With nutrient addition, increases of nitrogen containing metabolites were significantly higher in plant leaves and roots along with significant increases in tyrosine derived alkaloids, serotonin, and synephrine. Glycerol was also found to be significantly increased in the leaves as well as the ectorhizosphere. These differences provide insight into how C4 grasses adapt to changing nutrient availability in soils or with contrasting fertilization schemas. Gained knowledge could then be utilized in plant enhancement and bioengineering efforts to produce plants with superior traits when grown in nutrient poor soils.

Application of precision farming technologies for chemical protection of grain crops

The current trend of development of agricultural production brings heightened requirements to the quality and safety of products forcing the producers to change the technologies profoundly with providing balance between gross output of production and its safety, and maintaining the stability of agro-ecosystem. The main directions of implementation of this trend is application of technologies of precision farming which constitutes in pre-dosed and addressed fertilizing and application of chemical materials to protect plants. One of the directions of efficiency improvement in the sphere of plant protection is the application of GPS-navigation which monitors the quantity of applied liquid and moving aggregates used for herbicide application. While carrying out the study of efficiency of application of the parallel driving system with the use of GPS-navigation during the chemical weeding of barley seeds of the sort “Otra” in conditions of the Vologda region it was found out that application of the system of parallel driving allowed reducing the amount of sections with the repeated herbicide treatment. This leads to the lowering of quantity of applied herbicides and positively affects the grain crop yield providing the reduction of costs for dilution to treat more than 1, 2 times.

The Perennial Grain Crop Thinopyrum intermedium (Host) Barkworth & D.R. Dewey (Kernza™) as an Element in Crop Rotations: A Pilot Study on Termination Strategies and Pre-Crop Effects on a Subsequent Root Vegetable

Intermediate wheatgrass (IWG) may benefit soil fertility in crop rotations. To investigate termination strategies, i.e., autumn ploughing (AP), autumn harrowing (AH) and spring harrowing (SH) on a five-year-old IWG stand, a pilot study was performed. After the treatments, beetroots were sown and the IWG plants were counted twice during the beetroot growing season. The number of IWG plants was highest (20) after the SH strategy, intermediate (14) after the AH, and lowest (3) after the conventional termination strategy, AP. After the first plant count, the plots were subject to mechanical weeding in the form of a stale seedbed (i.e., harrowing twice before sowing). At beetroot harvest, the number of IWG plants was low (3 in SH and AH, 0 in AP) and similar between the treatments. The beetroot production was highest after AP and lowest in SH, and intermediary in AH, which showed no difference from AP and SH. At beetroot harvest, the weed biomass did not differ between the termination strategies. The weeds were mainly annuals. There were no differences in soil bulk density between termination strategies. Our results show that shallow soil tillage is enough to terminate IWG, as long as it repeated. We suggest further studies that investigate the dynamics of crop sequences with IWG, and how to benefit from this crop in rotations.

Long-term forecast of heavy metals content in wheat grain under changing climate conditions

Using the system approach, we have developed a simulation model for the long-term forecast of the content of toxic chemical elements in grain crop yield. The study was carried out by the example of wheat cultivated in Altai Krai — one of the main grain-producing regions of Russia. Wheat crops were sampled in 10 municipal districts of Altai Krai, which characterize seven different edaphic-climatic zones. The average long-term values of mean monthly air temperature and monthly precipitation for each sampling area were identified using GIS and data of the Interactive Agricultural Ecological Atlas of Russia and Neighboring Countries. A total of 19 chemical elements were considered, i.e. Pb, As, Cd, Hg, Na, Mn, Zn, Cu, Fe, Co, etc. It is shown that content of Pb, Na, Mn and Cu in wheat depend on climatic characteristics of the cultivation area. Regression dependences of element content on the average long-term air temperature and precipitation were established. Based on normalization and spatial generalization of air temperature and precipitation providing the uniform dynamics of their relative monthly values (in percent) throughout the study area, a forecast of their changes was made for 2030. A procedure for grain sampling, GIS technologies for processing meteorological and cartographic data, methods for predicting regional climate changes and establishment of quantitative relationships of chemical elements content in grain with climatic characteristics – all together make up the integral predictive simulation model for toxic substance content in grain crop yield. The model was used for estimation of Pb, Na, Mn, Cu changes in wheat by 2030. The lead (Pb) content in wheat crop delivered to elevators from certain municipal districts will exceed the maximum allowable concentration for breadgrain after 2030. Unlike Pb, Na, Mn, Cu, the content of other metals in wheat grain weakly correlate with long-term changes in air temperature and precipitation; therefore, it can hardly change significantly.

Spring vetch Mega mixed crops productivity at different seeding rates

Spring vetch is the most well-known annual legume forage crop. With the cultivation and application of various methods and terms of harvesting crops, not only for green fodder and hay, but also for haylage, silage, grain-growing, the requirements for the quality of the mown mass were reduced, but the need to create non-growing crops suitable for machine harvesting increased. In the gene pool of spring vetch, there are no forms with a strong, resistant to lodging stem, so the only way to solve the problem is to support the supporting culture. According to the results of research for two years, for the cultivation of vetch for green mass, the best option is vetch mixed with oats with a seeding rate of 1.2 million vetch, oats of 3 million germinating seeds per hectare. For grain cultivation, the best option is a mixture of vetch and oats with a seeding rate of 1.8 million and 3 million germinating seeds, respectively. For obtaining a grain crop for seed-growing purposes, the best option for two years of research is vetch mixed with spring wheat with a seeding rate of 1.8 and 3 million germinating seeds per hectare.

Resource-saving elements in onions growing technology on Nizhjeje Povolzhje region irrigated lands

The aim of this work was to prove many years research (at least two rotations) devoted to the problems of onion growing for industrial purposes on Nizhneje Povolzhje irrigated land. For these purposes, we have selected two farms with typical characteristics and production conditions in Astrakhan and Volgograd regions. During the period of the first rotation (2011-2015), we conducted competitive tests for the number of onion varieties and hybrids introduction and adaptation, as the result of which the zoned variety Volgodonets was selected for the second rotation (2016-2020) as a control and two regionalized hybrids of foreign selection Pandero F1 and Benefit F1. These samples were sown in the selected experimental plots as part of five-field vegetable-grain crop rotations in both farms. As the result, over five years of observations, the Benefit F1 hybrid showed the highest yield of 150.16 t/ha, Pandero F1 - 139.58 t/ha, and the Volgodonets variety - only 69.35 t/ha in Astrakhan region and 129.57 t/ha; 103.10 t/ha; 74.00 t/ha, respectively, in Volgograd region. The highest profitability indicator was provided by the Benefit F1 hybrid, which amounted to 87.94%.