Intensive Crop Rotations Research Articles

The Effect of Long-Term Crop Rotations for the Soil Carbon Sequestration Rate Potential and Cereal Yield

Depending on the type of agricultural use and applied crop rotation, soil organic carbon accumulation may depend, which can lead to less CO2 fixation in the global carbon cycle. Less is known about organic carbon emissions in different crop production systems (cereals, grasses) using different agrotechnologies. There is a lack of more detailed studies on the influence of carbon content in the soil on plant productivity, as well as the links between the physical properties of the soil and the absorption, viability, and emission of greenhouse gases (GHG) from mineral fertilizers. The aim of this study is to estimate the long-term effect of soil organic carbon sequestration potential in different crop rotations. The greatest potential for organic carbon sequestration is Norfolk-type crop rotation, where crops that reduce soil fertility are replaced by crops that increase soil fertility every year. Soil carbon sequestration potential was significantly higher (46.72%) compared with continuous black fallow and significantly higher from 27.70 to 14.19% compared with field with row crops and cereal crop rotations, respectively, intensive crop rotation saturated with intermediate crops. In terms of carbon sequestration, it is most effective to keep perennial grasses for one year while the soil is still full of undecomposed cereal straw from the previous crop. Black fallow without manure fertilization, compared to crop rotation, reduces the amount of organic carbon in the soil up to two times, the carbon management index by 2–5 times, and poses the greatest risk to the potential of carbon sequestration in agriculture.

Evaluation of Trichoderma isolates as biocontrol measure against Claviceps purpurea

Claviceps purpurea causes ergot, a floral disease of major cereal crops, such as winter rye and winter triticale. The dark sclerotia formed by C. purpurea contain numerous toxic ergot alkaloids, which pose a major health risk for humans and animals when ingested. The countermeasures against ergot infection are currently limited to intensive tillage, seed cleaning, crop rotation or integration of optical sorting machines to remove ergot from cereals before processing. However, these practices confer only a minor protective effect and are highly energy-demanding. Thus, more effective and sustainable plant protection measures to combat ergot infections in cereals are needed. The application of Trichoderma spp. as biological control agent has already proven successful against a wide range of phytopathogenic fungi. However, there is only minor scientific evidence about its protective capacity against C. purpurea in cereal crops. In our study, we therefore investigated the antagonistic potential of several Trichoderma isolates against C. purpurea and their ability to confer protection against ergot infection. In initial in vitro tests and confrontation assays, we quantified and compared the production of iron-chelating compounds and hydrolytic enzymes as well as the antagonistic activity against C. purpurea sclerotia and mycelial cultures. Several strains showed high antifungal capacity and growth inhibitory effects towards C. purpurea. Selected Trichoderma strains were then tested for their potential to protect rye (Secale cereale) plants from ergot infection within a greenhouse trial. Rhizosphere-inoculated plants displayed a decreased disease severity compared to plants that had been sprayed with Trichoderma spores above-ground. Gene expression analysis by reverse transcription quantitative PCR also indicated the induction of systemic defense reactions. Overall, our data suggest that individual Trichoderma isolates possess a high antagonistic potential towards C. purpurea, which could be effective by direct mycoparasitism and by inducing systemic plant resistance, and therefore provide important guidance towards the development of Trichoderma treatments of cereals as biocontrol measure against ergot.Graphical abstract

Integrating conservation agriculture with intensive crop diversification in the maize-based organic system: Impact on sustaining food and nutritional security.

Developing an intensive sustainable model and feeding a rising population are worldwide challenges. The task is much more daunting in the North Eastern Himalayas, where, low productive maize (Zea mays)- fallow is the main production system in the upland. To increase farm productivity, nutritional security, and energy dietary returns while maintaining environmental sustainability and economic viability, short-duration crops must be included in the maize-fallow system. A field study was conducted in sandy clay loam soil with a randomized complete block design with three replications for three continuous years (2018-2021) under organic management with two crop management practices, viz., (i) conservation agriculture and (ii) conventional agriculture, and six crop diversification options, viz., (i) maize-sweet corn (Zea mays saccharata)-vegetable pea (Pisum sativa) (M-SC-VP), (ii) maize-sweet corn-mustard (Brassica juncea) (M-SC-M), (iii) maize-sweet corn-lentil (Lens culinaris) (M-SC-L), (iv) maize-sweet corn-vegetable broad bean (Vicia faba) (M-SC-VB), (v) maize (local)-vegetable pea (M-VP), and (vi) maize (local)-fallow (M-F). The results showed that, the average system productivity was 5.3% lower for conventional agriculture than conservation agriculture. System carbohydrate, protein, fat, dietary fiber, and dietary energy were ~6.9, 6.8, 7.8, 6.7, and 7%, higher in conservation agriculture than in conventional agriculture, respectively. Similarly, system macronutrients (Ca, Mg, P, and K) and system micronutrients yield (Fe, Mn, Zn, and Cu) were, 5.2-8% and 6.9-7.4% higher in conservation agriculture than in conventional agriculture, respectively. On average, over the years, crop diversification with M-SC-VP/M-SC-VB intensive crop rotation had higher system productivity (158%), production efficiency (157%), net returns (benefit-cost ratio) (44%), and dietary net energy returns (16.6%) than the local maize-vegetable pea system. Similarly, the M-SC-VP/M-SC-VB system improved the nutritional security by improving Ca, Mg, P, K, Fe, Mn, Zn, and Cu yield by 35.5-135.7% than the local M-VP system. Conservation agriculture with M-SC-VP/M-SC-VB rotation showed significantly (p < 0.05) higher productivity, carbohydrate yield, protein yield, fat yield, and dietary fiber production. It is concluded that conservation agriculture improved soil health and performed better than conventional agriculture in maize-based intensive cropping systems. Overall results indicate that crop diversification with M-SC-VP/M-SC-VB can potentially increase calorie and protein consumption and farm profitability.

Productivity, quality, and nutrient uptake of intensive forage crop rotations based on corn in sandy soil (northern Morocco)

&lt;span&gt;Intensive dairy farming systems in the sandy soil of northwestern Morocco are based on three successive forage crops per year, including corn. The aim was to evaluate the productivity and the quality of different intensive crop successions based on corn in sandy soil. Three forage crops per year (winter, spring, and summer cropping seasons) were tested according to six successions: 1. fallow-corn-corn, 2. oat-corn-corn, 3. berseem-corn-corn, 4. pea/triticale-corn-corn, 5. oat-soybean-corn, and 6. berseem-corn-soybean. Each succession of crops was evaluated in two years field experiment using a randomized complete block design. Results revealed that oat-corn-corn and pea/triticale-corn-corn successions produced the highest dry biomass (46.5 t ha&lt;sup&gt;-1&lt;/sup&gt; year&lt;sup&gt;-1&lt;/sup&gt;). The crop succession of berseem-corn-soybean resulted in the lowest biomass (30.8 t ha&lt;sup&gt;-1 &lt;/sup&gt;year&lt;sup&gt;-1&lt;/sup&gt;). The highest net energy for lactation was recorded at oat-corn-corn and pea/triticale-corn-corn successions (303 10&lt;sup&gt;3&lt;/sup&gt; MJ ha&lt;sup&gt;-1&lt;/sup&gt; year&lt;sup&gt;-1&lt;/sup&gt;). The crop successions based on one corn (oat-soybean-corn and berseem-corn-soybean) recorded the lowest net energy for lactation (195.5 10&lt;sup&gt;3&lt;/sup&gt; MJ ha&lt;sup&gt;-1&lt;/sup&gt; year&lt;sup&gt;-1&lt;/sup&gt;). The oat-corn-corn, pea/triticale-corn-corn, and oat-soybean-corn successions recorded the highest crude protein values (3.9 t ha&lt;sup&gt;-1&lt;/sup&gt; year&lt;sup&gt;-1&lt;/sup&gt;). Soil organic matter and the content of soil on total N, P, and Mg were similar for the different crop successions at the end of the experimental years.&lt;/span&gt;

Стратегічне управління продуктивністю агроценозів у системі осушуваного землеробства

Goal. To improve the zone agrotechnological aspects of growing market-oriented crops in the system of drained agriculture. Methods. The experiment and research were carried out using generally accepted methods of field and lysimeter experiments in agriculture and crop production. Results. The results of experimental research on conducting highly efficient managed agriculture on drained lands, which ensures the creation of the most favorable conditions for the formation of highly productive agrocenoses and the expansion of their productive functions in the Polissia zone, are given. The influence of purposeful optimization of the technological parameters of the main links of reclamation agriculture: water-air and nutrient regimes of the drained soil with the use of the crop rotation factor on the formation of the yield of the commercial grain of commercially attractive crops was studied. Fertilizer systems for intensive technical crops adapted to the conditions of Polissia were improved. The effect of additional regulation of the water-air regime of the drained soil following the requirements of crops (favorable conditions of moisture) on their productivity was studied. The standards for the consumption of biogenic nutrients for crop formation were updated and clarified. The economic parameters of the technologies — the break-even points at which effective cultivation of crops could be achieved — were determined. The productivity potential of the proposed intensive short crop rotation, aimed at market conditions of farming, was evaluated. Conclusions. Strategic management of water, air, and nutrient conditions of the soil with effective plant nutrition in the conditions of a perfect meliorative system makes it possible to increase the productivity of arable land in the Polissia zone by 2.8 times (from 40 t/ha to 110 t/ha), which ensures effective development of plant industry in this territory and rational use of the resource potential of drained lands.

Intensive crop rotations and residue quality increase soil phosphorus lability under long-term no-till in tropical soils

This study assessed soil Phosphorus (P) fractions and lability according to crops in rotation and crop residue P inputs under long-term no-till (NT) in weathered tropical soils. Two experiments were established in split-plot designs with fall-winter as the main plot and spring as the subplots. In one experiment, sunflower and triticale were grown in Typic Rhodudalf (TR) soil in fall-winter; in the other experiment, monocropped and intercropped ruzigrass and grain sorghum were grown in Rhodic Hapludox (RH) soil in fall-winter. In both experiments, sunn hemp, forage sorghum, and pearl millet were grown in the spring; an additional fallow treatment was established in spring in TR. Soybean was grown every year in the summer in both experiments. After 12 (TR) and 9 (RH) years, the crop residue quality (e.g. N content and lignin-N ratio) and P inputs of the various crops were assessed. In addition, soil P fractions were determined according to the Hedley procedure. High-quality residue enhanced P recycling by soybean under crop rotation with sunn hemp in both experiments, sunflower in TR, and ruzigrass in RH. Sunn hemp increased soil labile P by 13% compared with pearl millet in TR and by 40% compared with forage sorghum and pearl millet in RH. Forage sorghum in spring enhanced P mod-labile in TR, effect also observed for monocropped grain sorghum and ruzigrass in fall-winter in RH compared to both intercropped. In general, crop rotation under NT improved soil P lability, particularly the biological P pool, suggesting positive impacts from crop residue quality. The results of this study can be used to guide P fertilization strategies for NT cropping systems in tropical soils.

THE EFFECT OF LONG-TERM CROP ROTATIONS ON SOIL PROPERTIES IN SPRING BARLEY CROPS

Intensive farming and short crop rotations have encountered problems of soil degradation. Finding solutions to these problems as well as new challenges requires returning to old farming practices, adapting them to current issues. In 1965, a field experiment (crop rotation collection) was set up at the Experimental Station of Vytautas Magnus University, the significance of which not only did not decrease, but became increasingly more relevant. The object of the research is spring barley crops in cereal, Norfolk, field with row crops, intensive and for green manure crop rotations as well as continuous bare fallow. The aim of the research was to investigate the effect of long-term crop rotation combinations on soil properties in spring barley crops. Crop rotations with perennial grasses or manure fertilization have demonstrated a positive effect on soil properties. Improving the agrophysical properties also improves the biological and chemical soil properties. This tendency becomes apparent in the field experiment carried out for more than fifty years in the same place.

Double cropping and manure management mitigate the environmental impact of a dairy farm under present and future climate

CONTEXTStrategies are needed to reduce the environmental impacts of dairy farms, and these may become more important as our climate continues to change. Double cropping small grain and corn silages provides a strategy that can benefit dairy farms in the northeastern U.S. as they adapt to a longer growing season. Subsurface application of manure may also reduce nitrogen (N) and phosphorus (P) losses as the region faces warmer temperatures and greater precipitation. OBJECTIVEEvaluate whole-farm production, environmental and economic impacts of adopting these strategies on a representative dairy farm in central Pennsylvania under recent historical and projected midcentury climate. METHODSFarm management strategies were simulated using the Integrated Farm System Model to determine effects on crop yields, feed production, volatile, leaching and denitrification losses of N, sediment erosion, sediment-bound and soluble losses of P, farm-gate life cycle greenhouse gas emissions, fossil energy use, and production costs. RESULTS AND CONCLUSIONSDouble cropping increased and stabilized feed production by providing forage from a winter rye crop with less dependency on the summer crops of corn silage and perennial grasses. Summer crops are susceptible to summer droughts, which are expected to increase in this region due to warmer temperatures and increased evapotranspiration. Double cropping was more beneficial in the midcentury climate due to the projected increase in growing season length. Double cropping and subsurface injection of manure reduced total N losses by 12–18% and total P losses by 16–19%. Double cropping using broadcast manure application had a neutral environmental and economic impact on the farm. Adoption of these strategies provided a feasible adaptation and mitigation approach for future climate by reducing projected increases in soluble P runoff and ammonia emission caused by warmer temperatures and greater precipitation while maintaining and potentially reducing total farm production costs. SIGNIFICANCEWhole-farm simulation provides a tool for evaluating potential benefits and tradeoffs of novel technologies and strategies as agriculture adapts to changes in climate. Although these results are specific to a dairy farm in central Pennsylvania, they generally apply to dairy farms throughout the Northeast U.S. and climates where similar changes in temperature and precipitation are projected by mid-century. Our analyses suggest that use of a more intensive crop rotation (double cropping winter small grain and corn silage) along with improved manure application technology (subsurface injection) can help mitigate dairy farm environmental impacts now and even more in the future.

Geochemical fingerprint of agricultural liming as a regular management practice in Modern-period Basque farming

The Modern period in Europe is marked by the introduction of deep agricultural changes. In the Basque Country (northern Spain), the implantation of an intensive crop rotation was made possible by the expansion of agricultural liming, although the extent and implications of this practice have not been previously explored in depth. The present paper proposes a multidisciplinary approach to this question, based on the combined analysis of archival sources, toponymy, visual prospection focused on the presence of limekilns, and agricultural soil coring in four local contexts of the Atlantic Basque Country. The results show, for the first time, evidence of concurrent and widespread liming in this territory at the edge of the 18th century, with strong implications for the model of agricultural management in the communities involved. The spreading of mineral fertilisation reflects an intensification in the forms of agricultural management, in the framework of a new relationship between land and labour that emerged after the introduction of American crops. Continuous liming for more than 200 years exerted a deep impact in the analysed soils, with interesting socio-economic and ecological implications that are representative of the potential short-term effects that changing relationship between humans and their socio-ecological environment may produce in agricultural soils.

ECOLOGICAL POTENTIAL OF GRAIN PEGULUM CROPS IN MODERN INTENSIVE CROP ROTATIONS

The article discusses the ecological significance of leguminous crops grown in modern intensive crop rotation. In particular, the area under crops of common leguminous crops in Ukraine and the level of their productivity have been analyzed. A comparison is made with the acreage of the most widespread grain crops. The emphasis of the article is aimed at establishing the level of nitrogen fixation of leguminous crops, which have the largest sown areas in Ukraine. The volume of accumulation by these leguminous crops of by-products in the form of their straw and stubble is also calculated. A comparison is made according to these indicators with the most widespread grain crops grown in Ukraine. The data on the content of the main nutrients in the by-products of leguminous crops - nitrogen, phosphorus, potassium are given. On the basis of these indicators, a calculation was made of the accumulation of the main nutrients in the soil, which can come with the by-products of leguminous crops with an average yield of their seeds. We also compared the obtained indicators with the input of nitrogen, phosphorus and potassium into the soil with by-products of the most common grain crops. Based on this, a conclusion was made about the most effective leguminous crops, the cultivation of which in the modern intensive crop rotation contributes most to the stabilization of the agro-ecological state of the soil. According to the State Statistics Service in Ukraine in 2019, the largest sown area among leguminous crops belonged to peas - 347.0 thousand hectares, which is 61.3% in the structure of all leguminous crops. In total, the sown area for leguminous crops in Ukraine is 566.0 thousand hectares, which is about 2% of the total sown area and this is a very low indicator. Considering the average yield in Ukraine, beans can return more by-products to the soil - 3.5 t/ha, soybeans and peas - by 8.6% less, beans - by 37.1%, and least of all - chickpeas and lentils - 1.7 - 1.8 t/ha. The content of the main macronutrients in the by-products of all leguminous crops is similar and is: nitrogen - 10.0-12.0 kg/t, phosphorus - 3.4-3.6 kg/t, potassium - 4.6-5.0 kg/t. It has been proven that an increase in the area of leguminous crops in an intensive crop rotation will have a positive effect on the agro-ecological state of the soil. In particular, growing beans allows you to get the highest mass of by-products that can be ploughed into the soil - 3.5 t/ha. Also, by-products of beans are characterized by a high content of mineral phosphorus - 3.6 kg/t, which ensures the supply of all mineral phosphorus to the soil - 12.6 kg/ha of all leguminous crops, as well as potassium - 16.5 kg/ha. Soybean by-products are characterized by a high nitrogen content - 12.0 kg/t, phosphorus - 3.6 kg/t and potassium - 5.0 kg/t. This allows, after growing soybeans, to accumulate in the soil with by-products more mineral nitrogen - 38.4 kg/ha. Also, soybeans are characterized by a high symbiotic nitrogen-fixing ability among all leguminous crops - 120 kg/ha. By-products of leguminous crops have a high content of nitrogen - 2.3-2.7 times, phosphorus - 1.5-1.6 times compared to by-products of grain crops. Also, when plowing soybean by-products into the soil, there will be 2 times more mineral nitrogen and 1.1-1.3 times more phosphorus than when plowing winter wheat by-products. Key words: egumes, by-products, nitrogen fixation, nutrients, accumulation, soil.

Nitrogen Dynamics Following Incorporation of 3-Year Old Grassland Set-Asides in the Fraser River Delta of British Columbia

Short-term grassland set-asides (GLSA) have been incorporated into intensive annual crop rotations to improve soil quality. The legacy of the GLSA to subsequent annual crops, however, is not well understood. The objective of this study was to determine the impacts of 3-year-old GLSA on nitrogen (N) dynamics and the yield of the subsequent cash crop. A regional analysis was conducted over two years, utilizing eight production fields transitioning from GLSA, paired with fields in continuous annual crop rotation (ACR) with matching management. A controlled plot-scale experiment was also conducted on a single 3-year-old GLSA, comparing fertilizer types, rates, and timing of incorporation. In each experiment, soils were sampled every 10–14 days for ammonium (NH4+-N) and nitrate (NO3−-N), along with ion probes, installed near the rooting zone to track plant available nitrogen (PAN) throughout the season. The results from the regional analysis are confounding, in 2015 showing that GLSA supplied an additional 18 kg PAN ha−1 compared to ACR but showed no PAN benefits in 2016. The controlled plot-scale experiment highlighted the importance of fertilizer type to subsequent PAN, showing synthetic treatments consistently supplied more PAN than organic. The results from this study suggest that 3-year-old GLSAs can potentially improve PAN to subsequent crops depending on how they are managed.

Dynamics of ammonia oxidizers in response to different fertilization inputs in intensively managed agricultural soils

Ammonia oxidation, the rate-limiting step of autotrophic nitrification, is carried out by ammonia-oxidizing archaea (AOA) and bacteria (AOB) that differ in their physiology and metabolic pathways. However, there has been little field investigations on the dynamic responses of ammonia oxidizers to different fertilizer inputs in intensive crop rotations. Here, we examine the soil potential nitrification rates (PNR), abundance and communities of AOB and AOA across different growth stages of wheat and maize at two soil depths (0–20 and 20–40 cm) under three fertilization regimes, namely zero fertilization (CK), chemical fertilizer (NPK) and partial replacement of the chemical fertilizer nutrients with organic manure (NPKM). Soil PNR was higher in the surface soil than in the subsoil in the wheat season, but no significant difference was observed in the maize season. Fertilization especially NPK treatment increased soil PNR, and the effect was more pronounced in the surface soil in the wheat season. The influence of soil depth on the abundance and communities of AOA and AOB was greater than that of fertilizer regime or plant growth stage across wheat and maize growth stages. The differences of ammonia oxidizers communities were mainly attributable to soil total nitrogen, organic carbon and soil moisture contents in the two depths. The abundance of AOB decreased more sharply than that of AOA with increasing soil depth. In general, application of NPK only increased AOB abundance in both wheat and maize seasons, whereas NPKM treatment increased AOB abundance only in the maize season (except in the subsoil at harvest). Generally, soil PNR was correlated with AOB and AOA abundances except for AOB in the subsoil in the wheat season and AOA in the surface soil during maize growth. Fertilization regime did not increase AOA abundance or alter AOA communities across all soil depths and plant growth stages. Our results indicate that the ammonia oxidizers differ greatly in responses to fertilization regimes and the changes are associated with soil depth and crop growth stage. The dynamics of soil microorganisms should be integrated into fertilizer and crop management to achieve sustainable agricultural systems.

MICROCLIMATIC CONDITIONS AND PHYSICO-CHEMICAL PROPERTIES OF SOIL IN INTENSIVE ECOLOGICAL VEGETABLE CROP ROTATION IN HIGH TUNNEL

In 2014–2015 at the experimental station of the University of Agriculture in Kraków, situated in Mydlniki near Kraków, Poland, experiments with intensive crop rotation in a high tunnel were conducted. The objectives concerned microclimatic zones in the tunnel and the yield and quality of butterhead lettuce (spring), cucumber (summer), and butterhead lettuce (autumn). Besides the properties of the soil in the high tunnel, a crucial role was played by microclimatic factors. The measurements showed variations in solar radiation, temperature and air humidity depending on the zone in the tunnel and the weather. Higher temperature in the centre of the tunnel was conducive to obtaining greater yields of spring lettuce and cucumber. In the spring and summer periods, the amounts of dry matter and total sugars in the edible parts of the cultivated vegetables were higher in the eastern and central zones of the tunnel. In the autumn, with less solar radiation, the amount of sugars in lettuce leaves was greater in the western zone. There was observable influence of the location in the tunnel from which samples were taken for analyses (zonal effect) on some physical parameters of the soil (bulk density, water capacity, and water-stability index).

Effect of cropping system and tillage practices on soil physical properties and maize growth

Conservation practices (CA) are one of the most suitable options to improve productivity and ensure food security. Conservation agriculture (CA) practices such as zero tillage (ZT) and permanent raised beds (PB) accelerate deposition of soil organic matter, reduce compaction and bulk density. Therefore, we analysed the effect of three medium-term tillage practices and three intensive crop rotations on selected physical properties of soil. The tillage practices consist of ZT, PB and conventional tillage (CT) in main plots and three crop rotations (MM, maize–maize; MW, maize–wheat; MC, maize– chickpea) in subplots. The experimental design was split-plot with three replications. After 7 years, we observed a significant positive effect of CA practices on soil organic carbon (SOC) content, soil compaction, bulk density, root length density (RLD) of maize. Thus, our medium-term (≥5-years) study showed that the combination of CA (PB and ZT) practices and appropriate choice of rotations (MC) appears to be the most appropriate option for restoration and improvement of the soil health of medium to coarse textured Inceptisols through the accumulation of soil organic matter (SOM) and improvement in soil physical properties.

Effect of increasing soil carbon content on tobacco aroma and soil microorganisms

Soil carbon pool, the largest carbon pool in any terrestrial ecosystems, has been disrupted owing to high rates of fertilization and intensive crop rotation. Reduction of soil carbon caused decreases of tobacco quality. Firstly, the correlations between soil types (purple soil and paddy soil from the tobacco region in southern China) and tobacco aroma compounds were analyzed in this research. It was showed that the soil carbon pool is closely correlated with tobacco aroma. Secondly, effect of the soil carbon content on soil microorganisms were analyzed. The results indicated that improvement of the soil carbon increased the tobacco aroma and the abundance of Lactobacillales and Oceanospirillales. The present study revealed the correlations between the soil carbon, microbial community structure and tobacco quality, demonstrating the importance of improving the soil carbon for increasing tobacco quality.

State and use of land resources in the Republic of Tuva of the Russian Federation

The area of the Republic is 168,604 km2 (3.28% of the territory of the Siberian Federal district, 0.98% of the area of the Russian Federation - the 20th in terms of area). Tuva basin, stretching more than 400 km from West to East along the Yenisei river, is an open hilly steppe space, located at altitudes from 500 to 1200 m. Mountain ranges, crossing it, divide the basin conditionally into three parts: Chemchik, Ulug-Khem and Turano-Uyuk. Of the total land area, most of the land is classified as forest land (64.5%), agricultural land accounts for 19.9% of the main specialization of livestock (mainly sheep and dairy cattle, goat and horse breeding). The area of farmland is more than 4.5 million hectares. The peculiarity of the pastures of Tuva is the ability to use their considerable part all year round for grazing cattle and livestock. In the conditions of the high-altitude zone, a wide variety of types of territories determines the nature of land use. As we approach the mountain-foothill landscapes, the degree of development of the territory decreases, the share of agricultural land, the share of intensive types of agricultural land use (arable land, intensive crop rotations and so on) decrease. As the height increases, the cadastral value of land plots should be reduced, which is caused by an increase in the possibility of dangerous geomorphological, climatic, neotectonics, hydrological processes and an increase in the complexity of agricultural land use. In this regard, the basis for the formation of agricultural land use in the conditions of high-altitude zones should be the similarity of the types of natural environment.

The Impact of Plant Protection Systems on the Productivity of Soybean Varieties under Irrigated Conditions

The application of preparations of biological origin in the protection system of soybean grown under conditions of intensive irrigated crop rotations conforms to the modern tendencies of science and production development. The use of them contributes to solving ecological, production and social-economic problems. The study presents the three-year research on the efficiency of systems protecting soybean from pests and diseases based on biological and chemical preparations. The research was conducted in typical soil and climate conditions of the South of Ukraine. Zonal agricultural methods and generally accepted research methodology were used. The purpose of the research was to create a soybean protection system based on preparations of biological origin, ensuring high productivity of high-quality products reducing a negative impact of the crop production on the environment. The study emphasizes that, under irrigated conditions of the South of Ukraine, the application of biological preparations has a positive impact on the indexes of growth, development and formation of the elements of soybean yield structure. There was an increase in the crop biological weight by 13.8 % and 22.1 % and the number of seeds per plant rose by 11.6 and 14.6 % as a consequence of eliminating harmful organisms with the plant protection systems. The larger ground mass was formed by medium-ripe varieties Danai and Svyatogor, on which the increase from protection measures was higher. Weight 1000 pcs. the seeds did not undergo significant changes. It is established that the larger seeds were formed by Danaya and Svyatogor varieties, in which the average weight is 1000 pcs. seeds were 142 and 136 g, respectively, while in the variety Diona this figure was 133 g. There was an increase in the height of the lowest pod when the total plant height rose. For medium-ripe varieties was characterized by a higher attachment of beans, where the highest values of this indicator acquired in the variety Svyatogor. The medium maturing soybean variety Danaia formed the maximum yield of 3.23 and 3.35 t/ha respectively, when biological and chemical protection systems were applied. The research establishes that the application of the bio-fungicide Psevdobakterin 2 (2.0 l/ha) in the crop protection system at the beginning of soybean flowering and the bio-fungicide Baktofit (2.5 l/ha) with the bio-insecticide Lepidotsid-BTU (10.0 l/ha) at the beginning of pod formation does not reduce the productivity of the soybean varieties under study considerably, when compared to the application of chemical preparations. The research determines that the soybean protection system under study ensures a decrease in the coefficient of soybean water uptake by 7.2-13.0 %, increasing the total water intake to an inconsiderable degree. Biologization of the soybean crop protection system leads to a reduction in production costs compared to the chemical protection system. Taking into account the needs for the collection of additional products, costs increase by an average of 1 thousand UAH/ha, while for chemical protection systems by 1.8 thousand UAH/ha. At the same time, the cost is reduced by 220-360 UAH/t and the profitability of growing crops is increased by 3.8-7.8 %. There has been a reduction in the burden of pesticides on the environment and the production of cleaner products. This indicates the prospect of using the biofungicides Pseudobacterin 2 and Bactophyte and the bioinsecticide Lepidocid-BTU on soybeans to protect plants from pests.

Effect of Nitrogen Levels and Foliar Application of Potassium Sulfate and Micronutrients on Growth and Yield of Maize Preceded By Wheat or Clover

Intensive crop rotation and imbalance fertilizer use have resulted in a wide range of nutrients deficiency in fields. For intensive cropping systems, the current recommended fertilizers rates need revision upwards with in balance ratio of vital micronutrients specific to crop to enhance stagnant yields. Two field experiments were carried out at the Agric. Exp. Sta., Fac. Agric., Cairo University, Egypt during 2014/2015 and 2016/2017 seasons to study the effect of preceding winter crops (Wheat or Egyptian clover), nitrogen levels (90, 120 and 150 kg N/fed.) and foliar minerals application (Control, potassiumsulphateand micronutrient compound of high zinc as well as their interaction) on growth and yield of Zea mays L. cv. single cross 131. The experimental design was split- split plot design with three replications. Results showed that maize planted after Egyptian clover provided the highest grain yield per plant (201.1 and 250.4 g), grain yield per fed. (3.474and3.487 ton) as well as harvest index (0.35 and 0.25 %) as compared to maize sown after wheat for both seasons, respectively. Increasing N rates from 90 to 120 kg/fed.and from 120 to 150 kg/fed.increased grain yield/plant by about 5.2% and 1.9% in the 1st season, corresponding to 2.9 % and 1.9% in the 2nd season, respectively. Increasing N rates from 90 to 120 kg/fed.and from 120 to 150 kg/fed increased grain yield/fed by about 24.6% and 12.8 % in the 1st season, corresponding to 25.9 % and 12.1 % in the 2nd season, respectively. Maize plants grown after Egyptian clover and receiving 150 kg N/fed.with the applied micronutrients and k foliarspray gave the highest grain yield/fed. (4.083 and 4.139 ton)in both seasons. The lowest value of grain yield/fed.was shown when maize was grown after wheat and receiving 90 kg N/fed.with foliar application of micronutrients and k sulfate in both seasons.Maize grown after Egyptian clover and receiving 120 kg N/fed.andfoliar application of micronutrients and k sulfate is recommended for maize production. On the other hand, maize grown after wheat withapplication of150 kg N/fed and foliar applicationof micronutrients and k sulfate is recommended for maize production.Regression analysis reveal the relation between the two variables, i. e., preceding crops (x) and Grain yield/fed (y) there was a linear relation, and, highly significant (P≤0.01) correlation coefficient (r=1) during the first and second seasons. Linear regression equation for N rates suggested that increase in one unit (30 kg/fed.) led to increase grain yield/fed.by 0.35 ton/fed.during the first and second seasons.

Intermediate crops as one of the factors of optimizing the application of fertilizers and increasing soil fertility

Saturation of crop rotation with intermediate crops compresses the time of agricultural works: harvesting the forecrop grown, preparing the soil, applying fertilizer, sowing the next crop. Regulation of water availability of plants makes all factors of productivity manageable. Wheat on green fodder responds positively to the extended sowing time and allows collecting feed or mass for the production of grass meal in the same sequence in the autumn and spring. Continuous use of arable land in intensive irrigated crop rotation provides a high total yield of green mass mixture and row crops grown after the bean-wheat mixture on ordinary irrigated chernozem and objectively provided by any combination scheme obtaining adequate total yield for some deviations concerning the early harvest or late sowing. Spring crops in intensive crop rotation with irrigation in the south of Russia are used as insurance crops in case of winter crops. In intensive crop rotations, they play a more important role of stubble crops. Zero tillage for crop after irrigation is not inferior in efficiency to plowing. The use of mineral fertilizers in the system of two crop field is an integral agricultural method, contributing to an increase in the yield of all crops.

Biochar application on paddy and purple soils in southern China: soil carbon and biotic activity.

Soil carbon reserves are the largest terrestrial carbon pools. Common agricultural practices, such as high fertilization rates and intensive crop rotation, have led to global-scale environmental changes, including decreased soil organic matter, lower carbon/nitrogen ratios and disruption of soil carbon pools. These changes have resulted in a decrease in soil microbial activity, severe reduction in soil fertility and transformation of soil nutrients, thereby causing soil nutrient imbalance, which seriously affects crop production. In this study, 16S rDNA-based analysis and static chamber-gas chromatography were used to elucidate the effects of continuous application of straw biochar on soil carbon pools and the soil microbial environments of two typical soil types (purple and paddy soils) in southern China. Application of biochar (1) improved the soil carbon pool and its activity, (2) significantly promoted the release of soil CO2 and (3) improved the soil carbon environment. Soil carbon content was closely correlated with the abundance of organisms belonging to two orders, Lactobacillales and Bacteroidales, and, more specifically, to the genus Lactococcus. These results suggest that biochar affects the soil carbon environment and soil microorganism abundance, which in turn may improve the soil carbon pool.