Agronomic Techniques Research Articles

Agroforestry and organic agriculture

Current conventional agriculture is considered unsustainable and inadequate to address great societal challenges such as climate change, environmental pollution, food security, dependence on fossil energy as well as the decline of natural resources and biodiversity. Many of these problems are related to agricultural specialization (i.e. monoculture) and the consequent simplification of the agroecosystem. In this respect, efforts aimed at improving individual agronomic techniques and at increasing the use-efficiency of external inputs (e.g. synthetic inputs, fossil fuels), without modifying the structure and functions of the whole system, appear to be insufficient to achieve sustainability in most conventional and intensive farming systems. Current organic farming systems adopting the so-called input substitution approach remain intensive and highly specialized and not necessarily able to significantly improve their sustainability. This would require system diversification and redesign of the agroecosystem to increase the spatial and temporal diversification of all its components and promote positive ecological relationships between them. Agroforestry is an agricultural approach based on the diversification of the agroecosystem production components (woody perennials, such as trees or shrubs, plus crops and/or livestock) and on the intensification of the agroecological relationships between these components. As such, it has transformative potential, providing an opportunity for increasing the sustainability of organic farming. In this article we review how the adoption of agroforestry practices could contribute to increasing sustainability in organic farming, and discuss the challenges and opportunities of this adoption.

The State of the Art of Agricultural Research on Maize Crop in Mozambique

This study mapped the agricultural researches on maize crop in Mozambique. A bibliographic research in the internet was carried out. Thus, we selected 72 studies related to maize crop in Mozambique. Descriptive statistics was used to group the studies according to year of publication and region that they cover. The main themes of the studies were grouped based on Commodity System Approach (CSA). The results point out that the scientific production on maize has relatively increased since 2011. 29% of studies address maize crop in entire country while 26% include other countries, mainly those neighbors of Mozambique. At the provincial level, Manica with 14%, Maputo with 7% and Tete with 7% are the provinces with relative high percentage of studies. Therefore, there is not relationship between the percentage of studies and the agricultural potential of the provinces in the country. The main themes of scientific production on maize are agronomic techniques for maize production (50%) and maize market issues (22%). Although post-harvest losses of maize are significant in Mozambique, only 2.8% of the studies analyzed this theme. Recently, some research on maize crop address transversal issues as environment, gender and nutrition. But the percentage of studies analyzing these themes is still low. Future studies are suggested to address themes linking transversal issues and maize crop. Maize storage and its market are other themes that deserve to be studied in the future.

Nitrogen fertilization in Brachiaria decumbens Stapf grass under degraded soil condition

Chemically degraded soils are found all over the world. Fertilization is an essential agronomic technique for recovering fertility and productivity in these areas. In this context, the objective was to recover the productive capacity of a degraded Red Yellow Argisol, grown with Brachiaria decumbens Stapf, in the presence of mineral fertilization with increasing amounts of nitrogen, evaluating the production of plant mass, plant height, tillering and water consumption. The experiment was conducted in a screened shelter and humidity control, according to a completely randomized experimental design. The treatments were organized in a factorial scheme, 6 treatments (without fertilization, 0, 30, 60, 90, 120 of nitrogen; 80 and 50, phosphorus and potassium for all treatments in g vase-1, respectively) corresponding to the amount of fertilizer applied in Kg ha-1, 4 cuts (performed every 30 days, starting 45 days after planting) and 5 repetitions. When fertilizing with 120 Kg ha-1 of nitrogen, it was obtained increase in fresh (655%) and dry (685%) mass when compared to the phytomasses of the treatment without fertilization, there was also an increase in the number of effective tillers and plant height, as the amounts of nitrogen applied increased in the soil. The maximum amount of nitrogen to be applied to the soil, in order to produce phytomass of B. decumbens in the condition of chemical degradation of the soil, obtained in the work was 120 Kg ha-1. In addition, the work allowed us to conclude that fertilization is an inexpensive and very important technique to recover the productive capacity of forage in the micro region of Brejo Paraibano, Northeast Brazil.

Effect of Losing Nitrogen Fertilizers on Living Organism and Ecosystem, and Prevention Approaches of their Harmful Effect

The world’s population is drastically increasing; therefore, an enormous amount of nitrogen and other fertilizers are used to produce enough food for their feeding. Furthermore, since the applied nitrogen amount is not completely absorbed by plants, its big proportion is released to the environment in different ways. The released nitrogen amount damages both humans’ health and the environment. Some technical and agronomical techniques help to minimize the loss of this nitrogen. The fertilizer's loss not only affects farmers' economic condition, but their effects are integrated. Nitrogen fertilizers pollute water, soil, air, as well as our foods. Leaching nitrate can cause eutrophication in sea, lakes, and water bodies. This condition poses a big threat to the lives of fish and other aquatic organisms. It also causes various diseases in humans such as blue baby syndrome, carcinoma, and others. For instance, Nitrate-N (NO3-N) leads to the blue baby syndrome, carcinoma, and other diseases in humans. NO3-N leaching stimulates the growth of blue-green algae and creates hypoxic zones in the water. Moreover, cyanobacteria produce toxins that affect the liver`, kidney, brain, skin, and other parts of the human body, as well as cause complicated diseases. Ammonia and nitrogen oxides contribute to acid rains and have adverse effects on ecosystems. Nitrous oxides (N₂O) deplete the ozone layer, a layer that prevents harmful rays from reaching the earth. N₂O contributes extremely to global warming due to its potentiality. Although Nitrogen fertilizers have contributed to produce high yields in the world, their excessive application has created different problems in our environment. To reduce nitrogen leaching, some agronomical, technical, and other practices are required to be used in the large and small farming system.

Analysis of soybean yield formation differences across different production regions in China

AbstractUnderstanding the yield gaps and its limiting factors under different soybean [Glycine max (L.) Merr.] production environments is essential in order to increase yield to meet plant‐based protein and vegetable oil requirements. Soybean yield data from the National Crop Varieties Test (NCVT) were analyzed to identify yield‐limiting factors and yield improvement measures in the four soybean agro‐ecological regions in China. The average yield was 2.70 Mg ha−1, with a unimodal distribution from North to South. The highest yield was in Huang‐Huai‐Hai Plain (HHH), followed by Yangtze River Valley (YRV), Northeast (NE), and Tropical and Subtropical region (TS). Seed weight was a major limiting factor of yield improvement for low‐yield farmfields, while pods per plant and seeds per plant were both limiting factors of yield improvement for middle‐ and high‐yield farmfields. Choosing improved soybean varieties in the right areas is the most critical factor in increasing yields. Selecting high‐yield soybean varieties with high seed weights should be the primary task to further improve the yield for NE region. Increasing seed number and seed weight by preventing pod shedding and abortion with chemical control techniques from flowering to pod formation should be the key yield‐increasing measures for soybean production in YRV and TS regions. Furthermore, attention should be paid to maintaining soil moisture and ensuring water supply in HHH region. Furthermore, advanced agronomic techniques, such as high‐precision sowing, proper plant protection controls, and proper fertilizer formulas based on soil testing, are also vital measures to improve soybean yields.

How Can Weedy Rice Stand against Abiotic Stresses? A Review

Weedy rice is one of the most common weeds in rice cultivation in many rice areas throughout the world and it is able to cause significant yield reductions. Weedy rice is characterized by a high biological diversity that permits different populations to be identified on the basis of their morphological and physiological traits. This variability contributes to its success in different environments and allows different abiotic stresses, which are intensified by climate change, to be faced. Taller plants, enhanced tillering, seed shattering and the presence of red pericarp, variable hull coloration and awn morphology, linked to a deeper seed dormancy, are some of the traits that help weedy rice to spread in changing environments. The higher phenotypic plasticity and genetic variability of weedy rice make it more able to cope with temperature variations, intermittent water availability, soil salinity, drought conditions and increased CO2 concentrations than cultivated rice. As these abiotic stresses will become more frequent in the future, weedy rice competitiveness may be higher, with a spread of infestations. Thus, the control of weedy rice should be based on an integration of different preventive and agronomic techniques, a sensible use of herbicides and the use of suitable rice varieties.

Influence of biological means of plant protection on the microbiocenosis of agricultural soils in arid climate conditions

Aim . To study the effects of a biological plant protection agent on the state of the microbiocenosis of agricultural soils in the arid climate of the Astrakhan region. Material and Methods . The objects of study were agricultural soils located in the Kamyzyaksky district of the Astrakhan region. During the experiment the soils were treated with Bacillus atrophaeus ACIM B ‐ 11474. Studies were carried out in accordance with generally accepted microbiological and agronomic techniques. Field experiments were undertaken according to the generally accepted methodology of field and vegetation experimentation in the fields of strategic partner LLC Nadezhda ‐ 2 when growing potatoes. Results . Agricultural soils were investigated for agrochemical, agrophysical and microbiological indicators. Microorganisms involved in the mineralization of organic matter occurring in soil and the mobilization of nutrients were identified. The effect of the agent on the intensity the mobilization processes in the soil and on the activation of decomposition and mineralization of organic substances has been established. The use of the agent helped reduce the number of micromycetes in the soil and on cultivated crops studied. Plant protection has an impact on reducing their incidence, increases potato yields, increases the mass of tubers and reduces the number of diseased tubers. Conclusion . The use biological plant protection agent has a positive effect on the formation of the microbiocenosis and on the phytosanitary condition of the agricultural soils studied, as well as improving the characteristics of agricultural products cultivated on them.

Leaf nitrogen metabolism during reproductive phase is crucial for sustaining lint yield of densely populated cotton genotypes

AbstractPlanting density and genotype choice are important agronomic techniques to achieve high crop yields. This study explored how planting density and genotypes affect cotton (Gossypium hirsutum L.) leaf N metabolism and lint yield. Treatments included three planting densities (low, 3.00 × 104; moderate, 6.00 × 104; and high, 9.00 × 104 plants ha−1) and two genotypes (Zhongmiang16 and J‐4B). A randomized complete block design with split plot arrangement was used. Planting density of 6.00 × 104 ha−1 positively influenced leaf physio‐biochemical attributes and boll production. The high planting density reduced lint yield by suppressing leaf soluble sugar, protein, amino acid, chlorophyll a, chlorophyll b, nitrate N and nitrite N content, nitrite reductase, and nitrate reductase activity. Moderate‐density crop produced 15.9 and 10.7% more lint yield than low‐ and high‐density planting, respectively. This high yield was the result of improved leaf level functioning (e.g., increased pigmentation and N metabolism during late reproductive growth), which increased C assimilation. Favorable leaf microclimate could also have sustained activities of leaf nitrate and nitrite reductase and increased amino acid and protein contents, with better distribution of N metabolic assimilates. Late reproductive structure development closely allied with leaf physiological attributes under a short growing season. Cotton genotypes, irrespective of their architectural variation, produced higher lint yield when grown at 6 × 104 ha−1 in a short cropping season.

Biostimulants as a Tool for Improving Environmental Sustainability of Greenhouse Vegetable Crops

Plant biostimulants have gained great interest from the agrochemical industry and farmers because of their ability to enhance nutrient use efficiency and increase abiotic stress tolerance in crop production. However, despite the considerable potential of biostimulants for the sustainable development of the agricultural sector, the environmental evaluation of the application of biostimulants is still missing. Hence, this is the first study that focuses on the environmental assessment of the biostimulant action of arbuscular mycorrhizal fungus Glomus intraradices and vegetal-derived protein hydrolysate on two greenhouse vegetable crops, spinach and zucchini squash, under different fertilization regimes. The life cycle assessment from a cradle to gate perspective, which covers all processes related to crop cultivation up to harvest, was carried out to calculate the carbon footprint of the production chain for these two crops. The results of the comparative analysis revealed that the CO2 equivalent emissions of both crops were reduced due to the biostimulant applications. In particular, the effect of the mycorrhization on the reduction of carbon emissions compared to the un-mycorrhized control was higher in zucchini plants under organic fertilization (12%) than under mineral fertilization (7%). In addition, organic fertilization increased the total carbon footprint of zucchini (52%) compared with mineral fertilization. The results also showed that an increase of nitrogen fertilization from 15 to 45 kg N ha−1 in spinach production enhanced the total CO2 emissions per ton of harvested leaves in comparison with treatments that involved the foliar applications of protein hydrolysate together with a lower nitrogen input; this increase was 4% compared to the unfertilized treatment with application of biostimulant. This study can support decision-making in terms of agronomic technique choices in line with sustainable development of vegetable crop production.

Determining optimal mulching, planting density, and nitrogen application to increase maize grain yield and nitrogen translocation efficiency in Northwest China

BackgroundThe combination of mulch with N fertilizer application is a common agronomic technique used in the production of rainfed maize (Zea mays L.) to achieve higher yields under conditions of optimum planting density and adequate N supply. However, the combined effects of mulch, planting density, and N fertilizer application rate on plant N uptake and N translocation efficiency are not known. The objective of this study was to quantify the interaction effect of mulch, planting density, and N fertilizer application rate on maize grain yield, N uptake, N translocation, and N translocation efficiency. The experiment was arranged in a randomized complete block design with three factors (2 mulch levels × 2 planting densities × 4 N fertilizer application rates) replicated four times.ResultsThere was a significant interaction among mulch, plant density, and N fertilizer on maize grain yield, kernel number per cob, N uptake, N translocation, and N translocation efficiency. Averaged over the 3 years of the study, total plant N uptake at silking ranged from 79 to 149 kg N ha− 1 with no mulch and from 76 to 178 kg N ha− 1 with mulch. The N uptake at silking in different plant organs ranked as leaf > grain > stem > cob. Averaged across all factors, the highest N translocation was observed in leaves, which was 59.4 and 88.7% higher than observed in stems and ears, respectively. The mean vegetative organ N translocation efficiency averaged over mulch, planting density, and N fertilizer application rate treatments decreased in the order of leaf > stem > cob.ConclusionsMulch, planting density, and N fertilizer application rate not only have significant effects on improving maize grain yield and NUE, but also on N uptake, N translocation, and N translocation efficiency. Our results showed clearly that under high planting density, the combination of mulch and moderate N fertilizer application rate was the optimal strategy for increasing maize grain yield and N use efficiency.

Effect of Grafting on the Production, Physico-Chemical Characteristics and Nutritional Quality of Fruit from Pepper Landraces.

Grafting is a widely utilized agronomical technique to improve yield, disease resistance, and quality of fruit and vegetables. This work aims to assess the effect of grafting and fruit ripening on the production, physico-chemical characteristics, and nutritional quality of fruit from Spanish local pepper landraces. Landraces “Cuerno,” “Sueca,” and “Valencia” were used as scions, and “NIBER®” as the rootstock. Two ripening stages of the fruits were sampled: green and red. Grafting improved the yield and marketable quality and did not negatively influence the physico-chemical and nutritional characteristics of the fruit. It was noteworthy that the bioactive compound contents and antioxidant capacity were more related to maturity stage and genotype, and red fruit had a higher antioxidant capacity than green fruit. However, in all the scions, grafting significantly enhanced lycopene content in both red and green fruit. Another important effect of grafting was the volatile compound composition evidenced by discriminant analyses, which was characterized for the first time in the fruit of these landraces. The rootstock and scion combination could be a way to improve not only the production, but also the fruit quality of peppers.

Cultivar × Management Interaction to Reduce Lodging and Improve Grain Yield of Irrigated Spring Wheat: Optimising Plant Growth Regulator Use, N Application Timing, Row Spacing and Sowing Date.

Severe lodging of irrigated spring-wheat in sub-tropical Australia has previously caused yield loss of between 1.7 and 4.6 t ha–1 (20–60% of potential yield). In response, agronomic management options were assessed for their ability to reduce lodging and increase grain yield, namely plant growth regulators (PGRs), timing of nitrogen (N) application, row spacing and sowing date, in combination with long and short duration cultivars across 15 irrigated environments from 2012 to 2016. Our study identified significant interaction between genotype, environment and agronomic management (G × E × M) for grain yield and lodging, although some combinations of agronomic techniques were broadly applicable across cultivars. PGR application improved grain yield of most cultivars in well-irrigated fields that had more than 120 kg ha–1 N (mineral N + fertiliser N) at sowing, with yield gains of up to 0.5 t ha–1 observed in both lodged and non-lodged fields. However, PGRs had little effect on grain yield when soil + fertiliser N at sowing was less than 80 kg ha–1 N. In-crop N application (compared to sowing N application) often improved grain yield of short duration, lodging resistant cultivars, but reduced the yield of long-duration, lodging susceptible cultivars in some environments. Narrow row spacing of 19 cm had the highest grain yield across cultivars in low lodging environments. At a severely lodged environment, narrow rows were the highest yielding for five out of six cultivars when PGRs were used, but was the highest yielding for only half of the tested cultivars when PGRs were not used. Cultivar × sowing date interaction for grain yield was also associated with the occurrence of lodging. Neither early nor late sowing had a consistent yield benefit across a range of cultivars, as lodging severity varied between sowing date depending on the timing of storm-induced lodging events. Lodging resistant long-duration cultivars had more stable grain yield across environments and increased grain yield in response to early sowing. Further research is needed to determine the optimum management strategy for new cultivars, because farmers do not always choose the most lodging resistant cultivars for reasons of cultivar disease resistance, grain quality and seed availability.

Ecosystem service function of green manure and its application in dryland agriculture of China

Dryland agriculture, with wide distribution and high yield potential, plays an important role in ensuring food security in China. It is currently limited by water scarcity, soil depletion, water and soil loss, and low non-renewable resource-use efficiency. Green manure has the potential to improve growth environment of crops and promote sustainable high-yield crops by increasing soil quality, balancing soil nutrients, and enhancing soil water-storage capacity. In addition, green manure has ecological benefits, including enhancing agroecosystem biodiversity, increasing soil surface cover degree, reducing ineffective nutrient loss to environment, improving air balance of farmland systems, and biological control of diseases, insect pests, and weeds. Under current scenario of intensified global climate change, environmental deterioration, and agricultural product demand changes, the traditional agronomic techniques of using green manure as a fertilizer cannot satisfy the requirements of agricultural development. Thus, it is necessary to strengthen the selection and bree-ding of green manure genetic resources for dryland agriculture, to develop a new regionalization of green manure, and to establish a cropping pattern based on green manure suitable for different regions. Furthermore, it is important to study and optimize the tillage and cultivation techniques to satisfy modern production and to establish an evaluation system for the comprehensive benefits of green manure. It is needed to establish a green manure application pattern that enables resource and ecological protection for improving ecological environment and economic efficiency of dryland agriculture and provides theoretical basis and technical support for exploiting green manure benefits.

Allelopathic and intraspecific growth competition effects establishment of direct sown Miscanthus.

High yielding perennial crops are being developed as a sustainable feedstock for renewable energy and bioproducts. Miscanthus is a leading biomass crop, but most plantations comprise a sterile hybrid Miscanthus × giganteus that is clonally propagated. To develop new varieties across large areas, rhizome cloning is inefficient, time consuming and expensive. Alternative approaches use seed, and in temperate regions, this has been successfully applied by raising seedlings as plug plants in glasshouses before transfer to the field. Direct sowing has yet to be proven commercially viable because poor germination has resulted in inconsistent stand establishment. Oversowing using seed clusters is a common approach to improve the establishment of crops and it was hypothesized that such an approach will improve uniformity of density in early Miscanthus stands and thereby improve yield. Sowing multiple seeds creates potential for new interactions, and we identified at least two inhibitory mechanisms related to seed numbers. Germinating seed produced allelopathic effects on nearby seed thereby inhibiting plant growth. The inhibitory effect of Miscanthus seed on germination percentages was related to seed number within clusters. An extract from germinating Miscanthus seed inhibited the germination of Miscanthus seed. The extract was analysed by HPLC, which identified a complex mixture including several known allelopathic compounds including proanthocyanidins and vanillic acid. There was also evidence of root competition in soil in a controlled environment experiment. When the experiment on competition was replicated at field scale, the establishment rates were much lower and there was evidence of shoot competition. We conclude that the numbers of seed required to ensure an acceptable level of establishment in the field may be economically impractical until other agronomic techniques are included either to reduce the inhibitory effects of higher seed numbers or to reduce oversowing rates.

Features of identification of stages of growth of grain sorghum

Purpose. To study the stages of growth of grain sorghum on the example of the application of the Vanderlip and Reeves scale for the study of sorghum varieties of domestic selection.Methods. Field research was conducted during 2012–2018 in the soil and climatic conditions of DP DG “Salyvinkivske”, located in the Right-Bank Forest-Steppe Zone of Ukraine. Grain sorghum varieties of domestic selection were used for research and the peculiarities of the manifestation of growth stages were identified visually and on the basis of the peculiarities of sorghum plant organ formation at the embryonic level.Results. The Vanderlip and Reeves scale describes the stages of sorghum growth on a scale from 0 to 9 and is based on the visual manifestation of the traits. It is determined that at the stage of emergence (Stage 0) the influence of environmental factors and agronomic techniques is critical. But in phase 3 of the leaves (Stage 1) the plants cannot compete effectively with the weeds. In phase 5 of the leaves (Stage 2) the plants are sensitive to the negative effects of pests and weeds. Also, lack of nutrients, moisture or drought can significantly reduce yields. Differentiation of the growth point (Stage 3) corresponds to the period of rapid growth of sorghum plants, and therefore the lack of mobile forms of nitrogen can cause growth restrictions. But during the appearance of the flag leaf (Stage 4) on the level of productivity of sorghum plants are factors of lack of sufficient nutrients and moisture in the soil, it is necessary to continue pest control. During the ejection of panicles (Stage 5) and flowering (stage 6), plants react most critically to the provision of moisture and the onset of the driest conditions of the growing season. At the stage of milk ripeness (stage 7), drought slows down the rate of grain filling, and excessive moisture contributes to the development of diseases.Conclusions. Using the Vanderlip and Reeves scale to identify growth stages does not require special knowledge of the peculiarities of the formation of sorghum at the embryonic level. At the same time, it is comparable to other scales and evenly covers the main phases of plant growth and development.

Blessed Thistle Growth, Essential Oil Content, Yield and Composition as Influenced by Plant Density and Nitrogen Fertilizer

Blessed thistle (Cnicus benedictus L.) is an abundant resource with huge phytochemical and agronomic potentials. Their variation in response to agronomic techniques needs to be explored. Field studies were laid out to assess plant density and nitrogen fertilizer (N) effects on blessed thistle plant height, branches number (m-2), vegetative variables and RGR (relative growth rate), CGR (crop growth rate), LAR (leaf area ratio), NAR (net assimilation rate), as growth variables along with blessed thistle essential oil content, yield and compositions in two growing seasons. A three replicated factorial combination of plant densities (5, 10, 15, 20 and 25 plants m-2) and N levels (0, 50, 100 and 150 kg ha-1) in a randomized complete-block design were conducted. Addition of 100 kg N ha-1with 15-20 plants m-2caused a significant increase in vegetative and growth variables. Although the essential oil content declined by 28 and 39 % as N rate level rose from 0 to 150 kg ha-1, essential oil yield peaked at 40-80 kg N ha-1 in both years. The GC and GC/MS analysis showed that eicosane was the dominant component of the essential oil (31-65 %), followed by isopropyl hexadecanoate (5.7-9.2 %), octadecane (3.5-10.5 %) and cryptomerione (3.1-7.1 %) which presented variations across the treatments. Application of N resulted in a decrease in the eicosane and an increase in the proportion of isopropyl hexadecanoate, octadecane and cryptomerione. It can be concluded that optimizing agronomic management techniques could be an effective approach to improve growth, essential oil content and composition of the plant.

Soil chemical attributes in coffee growing with different agronomic techniques

The objective was to evaluate the effects on soil chemical attributes in a coffee growing area, according to different agronomic techniques used and their associations. The experiment was conducted in the field, in an experimental area at the Department of Agriculture - DAG, in Lavras - MG, from January 2016 to October 2018. Coffee was planted in January 2016, with Mundo Novo IAC 379-19 coffee seedlings, with a spacing of 3.6 m between rows and 0.75 m between plants in the planting row. The factors under study were arranged in a 3x2x5 factorial scheme, making a total of 30 treatments. In the plots, three soil managements were randomized (soil cover with polyethylene film, soil cover with brachiaria grass and conventional management of spontaneous vegetation). In the subplots, two types of fertilizers used in the fertilization of coffee trees were tested (conventional and increased-efficiency fertilizer). In the sub-subplots, four soil conditioners were tested (coffee husk, phosphogypsum, water retention polymer, organic compost), and the control without conditioner. Aimed to evaluate soil chemical attributes in coffee growing with different agronomic techniques through the evaluation of: soil pH, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), aluminum saturation (m) and base saturation (V%), by soil analysis carried out in October 2018 and leaf analysis in December 2018. It is noteworthy that the chemical attributes of the leaf were used only for principal component analysis through multivariate analysis. The use of fertilization (with conventional fertilizers or those with increased efficiency), combined with the application of organic compost or coffee husk, provide increased soil pH, as well as the use of ecological management of brachiaria grass. The use of organic compost as a soil conditioner increases phosphorus availability in the soil. Coffee husk, as a soil conditioner, is an efficient potassium source for the coffee crop. The use of organic compost and phosphogypsum increases the calcium and magnesium contents in the soil. The use of organic compost and coffee husk was efficient in increasing the base saturation (V%) grown with coffee. The use of organic compost, coffee husk and phosphogypsum reduced aluminum saturation in the soil. Treatments associated with the use of organic compost improve calcium, phosphorus and magnesium levels, increase pH and base saturation, besides decreasing aluminum saturation. Key words: Coffea arabica; soil managements; fertilizers; soil conditioners.

Влияние различных агроприемов на урожайность кормовых травосмесей в условиях Астраханской области

Влияние различных агроприемов на урожайность кормовых травосмесей в условиях Астраханской области

Optimization of NPK fertilization combined with phytoremediation of cadmium contaminated soil by orthogonal experiment.

In the current experiment, influence of NPK composition on the Cd contaminated soil-plant (Solanum nigrum L.) system as well as the phytoremediation efficiency were comprehensively studied. The composition of NPK was optimized for a sustainable phytoremediation and simultaneous agronomic technique in Cd-contaminated soil by orthogonal (L14) experiment, aimed to achieve plant productivity and maximum phytoremediation potential enhancement. Results showed that different treatments of NPK composition enhanced soil properties including saccharase, urease, catalase and acid phosphatase activities as compared to the control treatment, however, soil pH was slightly decreased by 3.64%~6.67% with different composition of NPK treatments. Plant biomass and Cd concentration in the aboveground part (stem and leaves) of S. nigrum were significantly (P<0.05) enhanced by 14.19%~48.97% and 38.50%~127.15% as compared to control plants with the addition of NPK fertilizers having different composition. Meanwhile, with the application of NPK fertilizer root/shoot Cd ratio and translocation factor (TF) was significantly decreased, however, bioconcentration factor (BCF) was increased as compared to control. Additionally, different composition of NPK fertilizers significantly increased photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids) and soluble protein in comparison to control. The activities of antioxidant enzymes in S. nigrum including ascorbate peroxidase (APX), catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) and glutathione reductase (GR) were increased, while malonaldehyde (MDA) and proline contents were decreased. Principal component analysis (PCA) showed that N3P2K2 treatment had the highest comprehensive score amongst other studied treatments of NPK composition, owing to its optimal composition for the investigated soil-S. nigrum system. Moreover, it was found that optimal composition (N3P2K2) of fertilizer resulted in increase of the plant resistance to Cd and the efficiency of phytoextraction. Therefore, it is suggested to all the small-holder famers and scientific community that precise composition of NPK fertilizer should be utilized according to soil properties, environmental conditions and plant requirements under Cd-stress condition in order to achieve maximum biomass, Cd uptake efficiency as well phytoremediation potential in moderately Cd contaminated soil.

Ecological and Economic Aspects of Land Desertification

Agricultural lands of the Russian Federation are intensively subjected to degradation and desertification as a result of irrational economic activity, which, against the background of unfavorable climatic factors, led to the destruction of natural ecosystems, degradation of the soil cover and ultimately to the creation of the unfavorable ecological environment. About 65 % of 130 million hectares of arable land, are exposed to water and wind erosion. Only by water erosion, 10 % of arable land lost 30–60 % of fertility and almost 25 % lost 10–30 %. As a result of deflation 25million hectares of agricultural land in the European part of the Russian Federation are degraded to varying degrees. The concept of the anti-degradation arrangement proposes to use environmental-economic geoinformational monitoring. Within the framework of this approach, the development of cartographic and mathematical models in three time environments is proposed: pre-agricultural, modern degraded, and certainly improved condition. The ecological and economic analysis makes it possible to synthesize information flows and analyze the most important degradation processes. The most important tool for implementing ther adaptive-landscape anti-degradation arrangement of agricultural landscapes is precision farming, which consists of several subsystems: decision-making, monitoring, agronomic techniques, specialized equipment, etc. Computer technologies and telecommunications allow to speed up and optimize production by combining technology and people, which helps reduce costs. Precision agriculture is impossible without using modern advances in collecting, processing and storage of various, often heterogeneous, agricultural information.