Perennial Legume Research Articles

Belowground Dynamics Influence Nitrogen Cycling and Crop Productivity in Diversified Corn Systems

Ecological nutrient management is a strategy that can help create resilient cropping systems and reduce the negative impact that agricultural systems have on the environment. Ecological nutrient management enhances plant-soil-microbial interactions and optimizes crop production while providing key ecosystem services. Incorporating perennial legumes into crop rotations and implementing no-till to enhance organic nitrogen (N) soil pools could reduce the need for inorganic N fertilizer inputs and lead to improved soil health. Plant and soil N pools need to be further quantified to understand how to enhance soil health across a range of agroecosystems. This paper aims to quantify plant and soil N pools in systems contrasting in crop perenniality (corn–corn, corn–soy, and corn–forage–forage) and tillage intensity (chisel till vs. no-till). Key plant, soil, and organismal metrics of N cycling were measured including fine root production, N-Acetyl-B-Gulcosaminidase (NAG) enzyme activity, and soil protein, nematode enrichment opportunist (fungal and bacterial feeding nematodes) and the nematode Enrichment Index. Fine root production was determined using in-growth mesh cores. Findings reveal that monoculture cropping systems with reduced tillage intensity and rotations with perennial legumes had significantly greater fine root N (FRN), soil protein and NAG enzyme activity (p < 0.05) relative to corn-soy. Additionally, nematode bacterivore enrichment opportunists (b1) were significantly reduced in corn-corn systems when compared to all other crop rotation systems. Correlation analyses indicated positive and significant relationships between FRN and soil protein (p < 0.05). These results demonstrate that lengthening crop rotations with perennial legumes and incorporating no-till management can increase organic N inputs, N mineralization rates, and organic N storage. Such ecological approaches to management have the potential to reduce the need for inorganic N inputs, while increasing long-term soil health and crop productivity.

Alfalfa and silage maize intercropping provides comparable productivity and profitability with lower environmental impacts than wheat–maize system in the North China plain

CONTEXTThe sustainability of winter wheat (Triticum aestivum L.) − summer maize (Zea mays L.) rotation (W − M), which is commonly practiced in the North China Plain (NCP), is threatened by severe groundwater deficits and environmental pollution due to excessive nitrogen (N) applications. OBJECTIVEConsidering the need for protein-rich forages by local livestock operations and the environmental benefits of growing perennial legumes, we propose that an alfalfa (Medicago sativa L.)-based system is worth introducing for field practice in the NCP. METHODSAn integrated evaluation was used in this four-year study to compare the agronomic, economic, and environmental performances of the following four cropping patterns: alfalfa monoculture (AA), alfalfa and silage maize intercropping with or without N input which is designed for local climate condition, maize monoculture with or without N input which is much-discussed as a resources-saving substitution and commonly practiced W − M. RESULTS AND CONCLUSIONSW − M obtained the highest aboveground dry matter (DM) productivity (P < 0.05) based on the highest irrigation water and N fertilizer consumption (P < 0.05) which caused considerable soil mineral N (Nmin) accumulation. The production cost of maize monoculture was the lowest as well as the DM yield, nitrogen accumulation and the net revenue compared with other systems (P < 0.05), moreover, there was a great risk of N losses during the offseason period. The alfalfa and silage maize intercropping with a low N input (120 kg ha−1 which is close to local practice for maize season) achieved 26.6%–34.9% more DM yield compared with AA and maize monoculture, and 12.5%–163.9% more N output compared with W − M and maize monoculture during four experimental years with same total economic revenue as W − M and AA did. The N input in alfalfa and silage maize intercropping dramatically improved the system productivity by assisting intercropped maize growth while did not lead to excessive Nmin accumulation within 0–210 soil layer compared with the intercropping system without N addition. The planting of alfalfa would not affect the water storage in the 0–60 soil layer after maize harvesting each year. For the effects of interspecific competition, the production of the intercropped alfalfa and maize was significantly decreased in 2020 and a three-year period of production is recommended for optimal use of the alfalfa and silage maize intercropping. SIGNIFICANCEAlfalfa and silage maize intercropping with an appropriate N input, which acquired comprehensive performances in terms of productivity, environmental impacts as well as economic profits, would be an optimal alternative system in the NCP.

Role of kura clover (Trifolium Ambiguum bieb.) of Vys variety in the growth of the forage base of the Tambov region

In the conditions of the forest-steppe of the Central Black Earth region, the issue of the sustainable development of forage production, which can be increased through the expansion of the range of cultivated species of perennial legumes, has become relevant. The need to increase the share of areas of perennial grasses is connected with the fact that natural lands and annual forage crops have low productivity. Forage grasses are characterized by a number of unique economically valuable properties and characteristics. In this regard, there is an urgent need to increase their sown areas, as well as to improve natural lands, create hayfields and pastures. One of the limiting factors is the insufficient provision of seeds for a new fodder crop - Vys clover of a kura variety. It is kura clover that plays an important role in the creation of a solid forage base for animal husbandry in the Tambov region. Kura clover (Trifolium ambiguum Bieb) is characterized by a number of valuable traits and properties. In this regard, for the first time in the Central Black Earth Region, its biology and morphological development began to be studied and the optimal terms and methods of sowing this perennial legume crop are being developed. It will allow obtaining stable seed yields. The technology for obtaining seeds of this forage crop of the Vys variety in the forest-steppe conditions of the Central Black Earth Region is currently in the process of development. Therefore, the ongoing research on agrotechnical methods of the cultivation of kura clover seeds is very relevant and the development of individual agricultural methods of its cultivation technology of seeds is one of the important tasks of forage production.

The Role Of Perennial Grasses In The Protection Of Soil Resources Of Erosive Ecosystems With Active Development Of Linear Erosion

We evaluated the stability of perennial legume and cereal grass species in artificial plant communities on permanent anti-erosion watercourses in the agroecosystems of the Belgorod region with active development of linear soil erosion. In the conditions of steppe and forest-steppe zones of the Belgorod region on permanently grassed watercourses in 2017-2019. varieties of perennial leguminous and cereal grasses: ‘Krasnoyaruzhskaya 1’ and ‘Krasnoyaruzhskaya 2’ (Medicago varia), ‘Kazatsky’ (Trifolium pratense), ‘Olshanka’ and ‘Ivica’ (Festuca arundinacea), ‘Streletsky’ and ‘Stepnyak’ (Lolium perenne)) obtained using local genetic material were studied. All varieties showed their resistance in agro-ecosystems with active development of linear erosion in the forest-steppe and steppe zones. Projective cover on watercourses in the steppe zone in all variants of experience was on average 83,4 %, in the forest-steppe zone - 86,3 %. In the third year of the tests on permanently irrigated watercourses in the steppe zone, the share of cereal and legume grass species was quite high and varied from 88 % in the variant M. varia + Onobrychis arenaria to 92 % in the variants M. varia + Bromopsis inermis and O. arenaria. In the forest-steppe zone, the share of cereal and legume grass species varied from 86 % in the variant L. perenne to 94 % in the variant L. perenne + B. inermis.

The South African perennial legume Lebeckia ambigua sustainably supports livestock production on infertile soils in rain-fed agro-ecosystems

Lebeckia ambigua is a perennial legume endemic to rangeland South Africa that is adapted to dry (< 400-mm annual rainfall), infertile and acidic (below pH 5.5Ca) soils. Although it is considered that the legume was grazed by mammalian ungulates during its evolution, little is known about its production, nutritive value for grazing animals or optimal management in an agricultural context, in either its centre of the origin or in Australia. Experiments were conducted to test the hypotheses that sheep would graze L. ambigua in autumn without adverse effects on either the animal or the plant. Lebeckia ambigua was established at two sites in Western Australia. In experiment 1, three grazing intensities were imposed by exclusion cages introduced during a single intensive grazing period, to provide differing residual pasture heights. The metabolisable energy and crude protein content of L. ambigua were more than 11.4 MJ/kg dry matter and 21%, respectively for all treatments. Un-grazed L. ambigua produced 1740 kg DM/ha while a single moderate or severe grazing reduced total biomass production by about 50% over 10 weeks post-grazing (P < 0.001). In experiment 2, continuous grazing of L. ambigua for 64 days had no negative impacts on biochemical health indicators of merino wethers. Grazing had no effect on plant density in either experiment indicating that L. ambigua is adapted to substantial grazing pressure in autumn. Lebeckia ambigua could become a valuable plant for sustainably increasing livestock production on infertile soils in rain-fed agro-ecosystems where other legumes fail.

Improvement of Forage Nutritive Quality of Alfalfa and Red Clover through Plant Breeding

Alfalfa and red clover are important perennial legumes for the production of high-quality fodder. The improvement of the forage quality of legumes is one of the strategic goals of breeding programs. Variation in quality traits (protein content (CP), neutral detergent fiber content (NDF), and acid detergent fiber content (ADF)) and relative feed value (RFV) among seven cultivars and 39 elite breeding populations of alfalfa and red clover was evaluated in the study. Significant differences were determined among the investigated cultivars/populations. Alfalfa populations L-8, 10, 12, 15, and 20 were characterized by a high CP content (up to 23.47%) and/or low NDF and ADF contents. The highest CP content in red clover was recorded in population CD-18 (21.89%), while the lowest NDF and ADF contents were determined in populations CD-19 and CD-4, respectively. High RFV was determined in alfalfa populations L-10, 12, 20, 15, 16, 8, 11, and 17 (prime fodder), and in red clover populations CD-4, 8, 16, 14, and 19 (premium-quality fodder). The identified superior alfalfa and red clover populations will be used to improve the nutritional value of forage crops in our breeding program, which will lead to the release of novel cultivars with improved forage quality.

Perennial, but not annual legumes synergistically benefit from infection with arbuscular mycorrhizal fungi and rhizobia: a meta-analysis.

Summary Many plant species simultaneously interact with multiple symbionts, which can, but do not always, generate synergistic benefits for their host. We ask if plant life history (i.e. annual vs perennial) can play an important role in the outcomes of the tripartite symbiosis of legumes, arbuscular mycorrhizal fungi (AMF), and rhizobia.We performed a meta‐analysis of 88 studies examining outcomes of legume–AMF–rhizobia interactions on plant and microbial growth.Perennial legumes associating with AMF and rhizobia grew larger than expected based on their response to either symbiont alone (i.e. their response to co‐inoculation was synergistic). By contrast, annual legume growth with co‐inoculation did not differ from additive expectations. AMF and rhizobia differentially increased phosphorus (P) and nitrogen (N) tissue concentration. Rhizobium nodulation increased with mycorrhizal fungi inoculation, but mycorrhizal fungi colonization did not increase with rhizobium inoculation. Microbial responses to co‐infection were significantly correlated with synergisms in plant growth.Our work supports a balanced plant stoichiometry mechanism for synergistic benefits. We find that synergisms are in part driven by reinvestment in complementary symbionts, and that time‐lags in realizing benefits of reinvestment may limit synergisms in annuals. Optimization of microbiome composition to maximize synergisms may be critical to productivity, particularly for perennial legumes.

A lucerne-digit grass pasture offers herbage production and rainwater productivity equal to a digit grass pasture fertilized with applied nitrogen

In recent years, livestock producers have widely sown tropical perennial grasses, such as digit grass (Digitaria eriantha), in the frost-prone summer dominant rainfall zone of eastern Australia. Tropical grasses require substantial nitrogen inputs to maintain water productivity and forage quality. Perennial legumes offer a potential nitrogen source for these perennial grasses when sown in a mixed sward. Lucerne (Medicago sativa) is the perennial legume most widely sown in grazing systems in south-eastern Australia. In this study, conducted over the period 2014–2018, we compared the soil water dynamics and rainwater productivity of pure stands of digit grass (fertilized with applied nitrogen), lucerne, desmanthus (Desmanthus virgatus) and leucaena (Leucaena leucocephala) and binary mixtures of digit grass (not fertilized with applied nitrogen) with each legume. We found that often growing season actual evapotranspiration (ETa) was similar among the treatments (P > 0.05), but rainwater productivity (kg DM/ha.mm) and proportion (%) of legume herbage mass were not (P < 0.05). Our results showed that the lucerne-digit grass mix was equally productive and efficient as fertilized digit grass (P > 0.05), particularly in the latter three seasons. However, lucerne dominated the herbage mass (c. > 67% legume). Leucaena production was delayed by frost and severely impacted by competition with digit grass, and generally underperformed both lucerne and desmanthus. This observation did always not hold when alfalfa mosaic virus (AMV) impacted desmanthus in specific seasons. Our experiment has shown that a mixed sward of lucerne-digit grass is highly productive and offered high rainwater productivity. Both desmanthus and leucaena, in mixes with digit grass, provided useful contributions of legume herbage mass, in specific seasons and under specific conditions, but both underperformed overall compared with lucerne.

Short-term response of soil greenhouse gas fluxes to alfalfa termination methods in a Mediterranean cropping system

ABSTRACT Soil acts as a natural source and sink for greenhouse gases (GHG) that are responsible for global warming and climate change. As the agricultural sector has an important impact on GHG (e.g., CO2, CH4, N2O) emissions, the definition of mitigation strategies is needed, especially for the Mediterranean climate areas that appear most vulnerable to climate change. The introduction of perennial legumes, such as alfalfa (Medicago sativa L.), falls within this scope, but it requires the application of a termination method aimed at reduction of GHG emissions. With the aim of assessing the short-term effects of two different alfalfa termination methods (Tillage vs No tillage plus herbicide), we defined the hypothesis that alfalfa termination by Tillage will increase soil GHG emissions compared to its termination by No tillage plus herbicide. Soil CO2, CH4 and N2O emissions were monitored over ~2 months (71 days; October–December, 2017) following alfalfa termination, using closed static chambers. The soil total GHG emissions after 71 days were significantly different for Tillage and No tillage plus herbicide: 311.90 ±21.21 versus 195.89 ±11.14 g CO2 equivalent m−2, respectively. For both termination methods, CO2 (up to a maximum value of 1.24 ±0.18 and 0.65± 0.07 kg C-CO2 ha−1 h−1, respectively) was the greatest contributor to the total soil GHG emissions (about 96%), compared to N2O (up to a maximum value of 0.37 ±0.13 and 0.31± 0.10 g N-N2O ha−1 h−1, respectively) and CH4 (up to a maximum value of −0.01 ±0.03 and 0.07 ±0.03 g C-CH4 ha−1 h−1, respectively). These data suggest that over the short term, legume perennial crop termination by No tillage plus herbicide better supports the purpose of climate regulations.

Ways to improve low-yield hayfields and pastures in arid areas

Relevance. An analysis of the development of feed production in the Stavropol Territory shows that at present, due to the low productivity of natural forage lands, the level of feed production does not meet the requirements for the development of animal husbandry. Illiterate anthropogenic influence in the dry-steppe regions of the region, where about 70% of the number of sheep and 30% of the number of beef cattle are located, led to the fact that up to 300 thousand hectares of hayfields and pastures were subjected to erosion and deflation. However, in recent years, the process of improving forage land has been reduced to a minimum. Therefore, the process of restoring the forage productivity of hayfields and pastures should be given close attention. To this end, in the zone of dry steppes we conducted research on the selection of perennial legumes and grasses of a new generation to create highly productive grassland agrophytocenoses of long-term use.Methods. The experiments were carried out in the conditions of arid and extremely arid zones of the Stavropol Territory. The objects of research were perennial legumes and cereals and their herb mixtures. Restoration of degraded hayfields and pastures was carried out by means of amelioration and superficial improvement.Results. According to our research, by enriching the degenerated grass with valuable legumes and cereals in terms of forage it is possible to significantly increase its productivity and quality. In extremely arid and arid zones the most effective mixtureswere ones involving 4 and 5 components, which yield reached 15.3–23.8 t/ha of green mass, and the yield of feed units per 1 ha was 1.9–2.6 t/ha. The increase in the productivity of the improved herbage had a positive effect on the feed capacity of the land, which increased to 0.83–1.30 conventional heads per 1 ha.

Оrganization of a green conveyor of zoned perennial grasses in the Far North

Relevance. The aim of the work is to create a green conveyor belt of perennial zoned grasses in floodplain meadows. For the first time in the Far North on the basis of field experience were studied species composition and mode of use of perennial grasses and legumes for green belt.Methods. The research was conducted in 2018–2020 in field conditions in the experimental field laboratory of horticulture of Yakut Scientific Research Institute of Agriculture named after M.G. Safronov in the Khangalassky ulus of the Sakha Republic (Yakutia). The soil of the experimental site is permafrost floodplain turf light loamy. Sowing was carried out in summer in the first decade of July.Results. The article includes data on the yield, chemical composition and nutritional value, and economic efficiency of perennial grasses. Over the years of research, the maximum yield was obtained from the grass mixtures of rumps (20)+ wheatgrass (16) — 4.0 t/ha of green mass, which is higher than the natural herbage by 2.4 t/ha of green mass. The yield of net sowing of sickle alfalfa (8 kg/ha) was 4.5 t/ha of green mass. The maximum yield from leguminous grass mixtures was provided by a two-component mixture of alfalfa (8 kg/ha) + stalk (10 kg/ha) — 4.9 t/ha of green mass. The highest content of crude protein when creating a green conveyor from single-species cereal crops is observed in red oatmeal — 18.2%, while the content of exchange energy is 9.1 MJ, feed units — 0.66, digestible protein — 122 g in 1 kg of dry matter. Of legumes and cereals the highest content of raw protein is provided by alfalfa (8 kg/ha) — 19.0%, while the content of exchange energy is 9.3 MJ, feed units — 0.70, digestible protein is 120 g per 1 kg of dry matter. When creating a green conveyor from grass stands, a high conditional net income is obtained when sowing boneless stalk (20 kg/ha) +w heatgrass (16 kg/ha) — 5688 rubles/ha, while the cost of production is 12,000 rubles/ha, the profitability is 90%.

Вплив технологічних заходів вирощування на розвиток кореневої системи та симбіотичну продуктивність еспарцету

An important factor in the feed industry intensification is the cultivation of perennial legumes, including sainfoin. The aim of the study was to determine the effect of mineral fertilizers and seed inoculation on the formation of the root system and the symbiotic productivity of different varieties of sainfoin grown on green fodder. Experimental studies were conducted during 2016-2018 on the research field of Forage Production, Land Reclamation and Meteorology Department, located at the NULES of Ukraine "Agronomic Research Station" on typical low-humus chernozem. According to the results of the research, it was established that on average in three years the biggest root mass - at the level of 52.7 t/ha was formed by sainfoin variety Amethyst Donetskyi with providing complete mineral fertilizer in the dose N45P60K90 and presowing seeds inoculation by Rhizotorphin. In plants of the same variant, the most developed symbiotic apparatus was also noted - in the flowering phase, the total number of tubers was 126 units/plant, and their weight was 3.444 g/plant. As a result of a strong root system of plants formation and a well-developed symbiotic apparatus, the amount of biologically fixed nitrogen under crops of sainfoin of variety Amethyst Donetskyi reached 143 kg/ha.

Productivity of long-term bean grass in single-species and compatible with anwless bromegrass feed agrophytocenoses

Goal. Establish the best perennial legumes when grown in single-species and compatible fodder agrocenoses with stokolos boneless and the effectiveness of the use of nitrogen-fixing and phosphorus-mobilizing bacterial preparations, as well as liming. Methods. General scientific − hypotheses, inductions and deductions, analogies, generalizations and special − field, laboratory, mathematical and statistical, computational and comparative. Results. Based on the generalization of literature sources, it is proved that the creation of sown grasslands, with high content of perennial legumes on meadows and arable lands, which are derived from intensive cultivation is one of the most promising areas of organic onion growing. Productivity of single-species crops of perennial legumes and their mixtures with boneless stalk on average for five years after the yield of 1 ha of dry mass in the version without fertilizers ranged from 5.12 to 8.38 tons, which is 1.7−2.5 times more in comparison with a grassy grass stand which is formed from one-species crops of a stokolos of a boneless. The highest productivity and level of symbiotic nitrogen accumulation (191−266 kg / ha) were provided by agrocenoses with the participation of alfalfa, and the lowest - meadow clover. The efficiency of soil liming during sowing of grasses and application of inoculation of seeds of perennial legumes with nitrogen-fixing and phosphorus-mobilizing preparations is given. Changes in the chemical composition of feed under the influence of the studied factors are also shown. Conclusions. Different types of perennial legumes and their mixtures with boneless stalk without fertilizers provide productivity in the range of 5.12−8.38 t / ha of dry weight, which is 1.7−2.5 times more than the grass cover, which is formed from single-species sowing of stokolos bezzostoy. Inoculation of perennial legume seeds with nitrogen-fixing and phosphorus-releasing microbiological preparations increases the productivity of perennial legumes and their mixtures with cereals by 2−6%, and soil liming before sowing – by 3−11%. The greatest effect is provided by the combined use of these bacterial drugs. Alfalfa sowing responds best to their use and liming.

Contrasting effects of soil pH on seed germination and early seedling growth of Calobota sericea and Lessertia frutescens subs. frutescens

This study evaluated the impacts of pH on the germination and early seedling growth of Calobota sericea and Lessertia frutescens subsp. frutescens, two perennial legume species found in the semi-arid rangelands of South Africa. The results of this study revealed that L. frutescens had higher seed germination under more acidic conditions, while C. sericea had higher seed germination under alkaline conditions. Similarly, L. frutescens seedlings were found to be larger under more acidic conditions, while C. sericea seedlings were larger under more alkaline conditions. Both species were able to germinate under all of the pH treatments, suggesting that they are adapted to a wide range of pH conditions, at least at the germination and early seedling growth stage.

Effects of plant diversity on semiarid grassland stability depends on functional group composition and dynamics under N and P addition

Exogenous fertilization could efficiently improve grassland productivity and promote grassland restoration. Increasing fertilization may profoundly affect community stability, whereas the underlying compensatory dynamics among functional groups in regulating grassland stability remain unclear. Three different grasslands, annuals forb (AF) community, perennial grass (PG) community and perennial forb (PF) community, on semiarid Loess Plateau were selected. We designed a 3-year split-plot experiment (main-plot: 0, 25, 50, and 100 kg N ha−1 yr−1; subplot: 0, 20, 40 and 80 kg P2O5 ha−1 yr−1) to explore how N and P addition affects community stability and its relationship with species richness, species asynchrony and functional group stability. Temporal stability differed largely between functional groups under N and P addition, perennial forbs or grasses had higher stability than perennial legumes or annuals and biennials. Decreased stability of PG and PF communities was primarily due to reduced species asynchrony under N addition alone, while it attributed to increased dominance of perennial legumes after P addition alone. 50 and 100 kg N ha−1 yr−1 combined with P addition significantly increased dominance of annuals and biennials, but decreased stability of annuals and biennials, which caused significant declines in stability of the three communities. Significant species richness decline induced by N and P addition only occurred in AF community, which suppressed AF community stability through reducing species asynchrony. AF community stability was regulated by additively negative effect of diversity decline and decreased annuals and biennials stability. Whereas, in PG and PF communities, nutrient-induced changes of functional groups stability were the main driver of community stability rather than diversity. Our study highlights the role of functional group composition and dynamics in regulating the effects of diversity on community stability and rational N and P combined addition was essential for conserving stability of different grasslands on semiarid Loess Plateau.

BEHAVIOR OF SOME LEGUMES SPECIES IN COMPLEX FORAGE MIXTURES

Human pressure on ecosystems, through economic or other activities, has a negative impact on ecosystem biodiversity, soil and water quality. Solutions are being sought worldwide to obtain food for humans but also for their animals, without further demanding the productivity and biodiversity of ecosystems. Crop systems based on mixtures of species with legumes, carefully designed, ensure the maximization of economic and environmental benefits. The present paper aimed to make an analysis of the behavior of perennial legumes (Medicago sativa, Trifolium repens, Trifolium pratense) in complex mixtures, in the Banat Plain. From the analysis of eight complex mixtures with perennial legumes in various variants and proportions of participation, it follows that they behave differently in mixtures in the three experimental years, under the given conditions. Medicago sativa retains the proportion of participation with which it entered the mixture in the first year of culture. In the second year it reduces its participation in mixtures by 5%, and in the third year of culture by another 5%, in most of the studied mixtures. The red clover (Trifolium pratense) retains the proportion of participation with which it entered the mix in the first year of cultivation but undergoes changes in both the second and third year (2020). Thus, it reduced its participation in the M4 and M8 mixture by 5 percent in the second year of cultivation and recorded an increase of 4 percent in the M3 mixture. White clover (Trifolium repens) has a different behavior in mixtures compared to the other two perennial legumes. In the first year of cultivation it retains its proportion in the mixture. In the second year (2019) it increases its proportion in the mixture by 5% in the mixtures M3 and M6 and keeps its proportion in M7. In the third year it increases its participation by five percent in the M6 mixture and decreases the proportion of participation by 10% in the M7 mixture. The increase and decrease of the proportion in the mixtures is attributed to competition between species for food, water, light and crop management. To select a mixture, the grower should first determine the benefits he expects. The cultivation of these mixtures could bring significant increases in production and therefore economic profitability.

Perennial legume intercrops provide multiple belowground ecosystem services in smallholder farming systems

Soil degradation is a major underlying cause of poverty and malnutrition in smallholder agrarian communities across the globe. Legume diversification, through polyculture or intercropping, is a strategy that increases yields and income while improving family nutrition. However, the potential for these legume-cereal intercrops to restore soil functions in smallholder fields remains uncertain, with many studies failing to detect increases in soil organic matter (SOM). In sub-Saharan Africa, smallholders typically grow maize either intercropped with short-lived annual food legumes or as a monoculture. Recently, a novel maize system which includes perennial legumes in the genus Desmodium as intercrops, known as “push-pull” (hereafter, PP) has been increasingly adopted by smallholders across the region. The yield, nutritional and economic benefits of the PP system are well-documented. We investigated the effects of PP maize intercropping on soil fertility compared to the predominant maize culture systems (hereafter, NPP) using soils from long-term experiments and smallholder fields in western Kenya. Maize-desmodium intercrops promoted SOM accrual and increased plant available phosphorus. In the long-term research station experiments soil organic N was 20% greater and labile organic N reserves were five-fold greater in PP compared to NPP soils. Despite equal P fertilizer application rates, extractable soil P was two-fold greater in PP compared to NPP soils. Soils under maize-food legume intercrops did not show any detectable accrual of SOM compared to maize monocultures. Soil benefits in smallholder PP fields tended to mirror those found in the controlled experiments. Taken together, our results demonstrate that the perennial legumes in PP system restore soil function and fertility. Developing additional well-designed intercropping systems that include perennial legumes could play a significant role in reversing the trajectory of soil degradation in smallholder farming systems while enhancing human well-being.

Soil Nitrate Nitrogen Content and Grain Yields of Organically Grown Cereals as Affected by a Strip Tillage and Forage Legume Intercropping.

Reducing tillage intensity and increasing crop diversity by including perennial legumes is an agrotechnical practice that strongly affects the soil environment. Strip tillage may be beneficial in the forage legume–cereals intercropping system due to more efficient utilization of biological nitrogen. Field experiments were conducted on a clay loam Cambisol to determine the effect of forage legume–winter wheat strip tillage intercropping on soil nitrate nitrogen (N-NO3) content and cereal productivity in various sequences of rotation in organic production systems. Forage legumes (Medicago lupulina L., Trifolium repens L., T. alexandrinum L.) grown in pure and forage legume–winter wheat (Triticum aestivum L.) strip tillage intercrops were studied. Conventional deep inversion tillage was compared to strip tillage. Nitrogen supply to winter wheat was assessed by the change in soil nitrate nitrogen content (N-NO3) and total N accumulation in yield (grain and straw). Conventional tillage was found to significantly increase N-NO3 content while cultivating winter wheat after forage legumes in late autumn (0–30 cm layer), after growth resumption in spring (30–60 cm), and in autumn after harvesting (30–60 cm). Soil N-NO3 content did not differ significantly between winter wheat strip sown in perennial legumes or oat stubble. Winter wheat grain yields increased with increasing N-NO3 content in soil. The grain yield was not significantly different when comparing winter wheat–forage legume strip intercropping (without mulching) to strip sowing in oat stubble. In forage legume–winter wheat strip intercropping, N release from legumes was weak and did not meet wheat nitrogen requirements.

Determining the content of nitrogen and some macroelements in the dry mass of perennial leguminous plants

The aim of this study was to determine the content of elements N, P, K, Ca, and Mg in the dry mass of perennial fodder legumes, mowed in the optimal growth phase. The experiment with perennial legumes of alfalfa (Medicago sativa), red clover (Trifolium pretense) and bird's-foot trefoil (Lotus corniculatus L.) was set up as a random block system in four replicates on valley-brown soil and was conducted for two years. The green mass of perennial legumes in the first and second mowing was harvested at the end of budding/ beginning of flowering phase. In the third and fourth regrowth, mowing of the biomass was done after 5 weeks. Immediately after each mowing, representative sample of green biomass was taken from each replicate of each legume tested. The content of nitrogen, phosphorus, potassium, calcium, and magnesium in the dry plant material was determined. The content of nitrogen and potassium in the fodder of alfalfa and red clover was higher in the first year of the study, which was not the case for bird's-foot trefoil. The dry matter of alfalfa on average had the highest content of nitrogen (39.8 g kg-1 DM) and calcium (19.6 g kg-1 DM), bird's-foot trefoil of phosphorus (10.6 g kg-1 DM) and potassium (26.1 g kg-1 DM), and red clover of magnesium (3.7 g kg-1 DM). In the dry mass of bird's-foot trefoil the average content of nitrogen was 39.0 g kg-1 DM, phosphorus 10.6 g kg-1 DM, potassium 26.1 g kg-1 DM, calcium 15.7 g kg-1 DM, and magnesium 3.5 g kg-1 DM.

ВИДОВОЙ СОСТАВ БЕСПОЗВОНОЧНЫХ (Invertebrata) ВРЕДИТЕЛЕЙ АГРОЦЕНОЗОВ КЛЕВЕРА ПОЛЗУЧЕГО (Trifolium repens L.) И АКТУАЛЬНОСТЬ ПРОВЕДЕНИЯ ЗАЩИТНЫХ МЕРОПРИЯТИЙ

The area of natural growth and the scale of economic use of white clover among perennial legumes are spatially one of the most global. Due to the constant presence of wild white clover in many natural phyto-cenoses of most agricultural landscapes of different geographical zones, a certain complex of phytophages has evolved from various classes of invertebrate animal organisms that feed on various parts of this plant and reproduce on it. With the introduction of white clover into the culture and the spread of production crops of this plant over large areas, more favorable conditions are created for uncontrolled mass re-production of pests, which can cause already economically and economically significant crop losses. White clover is affected by multi-eating and specialized pests, the damage from which is determined by their biological characteristics and climatic conditions. The high population of white clover crops with a complex of herbivorous invertebrates implies constant monitoring and control of the species composition of the harmful fauna of white clover crops in order to organize, if necessary, protective measures against them. This issue is especially relevant for seed crops. The main pests of seed stands are considered to be weevils of the genera Apion Herbs., Phytonomus Herbs., Sitona Germar., Hypera Germar., which can re-duce seed yield by 50% or more. To reduce the economic losses of the crop on white clover, an integrated protection system should be implemented using chemical, biological and agrotechnical pest control meas-ures based on taking into account their economic harmfulness thresholds. One of the important directions of increasing the efficiency of the production use of white clover is the development of varieties of this crop that are resistant to damage by pathogenic organisms and pests.