Perennial Forage Crops Research Articles

Performance and legacy effect of crop rotations on eastern Canadian dairy farms

AbstractCrop rotations on dairy farms in eastern Canada nowadays include fewer perennial crops and more nitrogen‐demanding annual crops. This study compared, over a 7‐year rotation cycle, the agronomic performance and the legacy effect of six crop rotations that varied in crop types (perennial or annual) and nutrient sources (mineral or organic). Crop yield and nutritive value were determined on a yearly basis and cumulated over the rotation cycle. The legacy effect was assessed by growing forage corn (Zea mays L.) in year 6 and soybean [Glycine max (L.) Merr.] in year 7 in all rotations. The legacy effect of perennial forage crops manifested with a 78% lower weed biomass at harvest of forage corn in year 6 and a 14% greater soybean yield in year 7. A greater soil‐derived corn nitrogen uptake in year 6 after repeated slurry applications indicated a modest legacy effect of organic fertilization on soil N supply capacity. The presence of perennial forage crops or the use of organic fertilization did not affect cumulative dry matter or crude protein production over the 7‐year rotation cycle. The addition of alfalfa (Medicago sativa L.) in mixture with perennial grasses improved forage yield (+26%) and nutritive value (greater digestible energy and crude protein concentration) in post‐seeding years. In perennial‐based rotations, adding alfalfa to grasses resulted in greater dry matter (+22%) and crude protein (+46%) productions over the 7‐year cycle despite a fourfold reduction in N fertilizer input, attesting to the high N use efficiency of perennial legume‐based cropping systems.

Long-term alfalfa planting mediates the coupling of soil water and organic carbon storage in a semi-arid area of the Loess Plateau, China.

The key to restoring arid and semi-arid ecosystems is maintaining soil water and organic carbon contents. Alfalfa (Medicago sativa L.) is a high-yield perennial forage crop and performs ecological functions as a drought-resistance leguminous herb. It has been widely planted for reconstruction of degraded soils in the Loess Plateau in northwestern China, but long-term planting may affect soil carbon-water coupling and lead to crop yield reduction. To maximize the benefits of reconstructed grassland, this study explored the couplings of soil water, organic carbon, and alfalfa productivity along a reconstruction chronosequence in a semi-arid area of the Loess Plateau. Space-for-time substitution approach was used to select different-aged stands of reconstructed grassland (1, 5, 7, 10, 15, 20, 30 years old). Alfalfa above-ground biomass (AGB), soil water storage (SWS), organic carbon storage (SOCS), and carbon-water coupling coordination degree (D) were measured in the 0-100 cm soil profile. Alfalfa AGB reached a peak in the 7th year, and the degradation began in the 10th year. Both SWS and SOCS varied nonlinearly with stand age. The greatest loss of SWS occurred in the 15th year (80-100 cm depth), whereas the largest increase of SOCS occurred in the 30th year (0-20 cm depth). There was a negative feedback relationship between AGB and SWS over the 30-year study period (Pearson r = -0.835, P = 0.098). AGB and SOCS initially showed a trade-off within the first 10 years (Pearson r = -0.7431, P = 0.2569), in contrast to their positive feedback in the 20-30th years (Pearson r = 0.9978, P = 0.0421). A decoupling between SWS and SOCS (D < 0.6) was observed after 12 years of alfalfa planting. For agricultural production, a greater supply of water and organic fertilizer is required from the 7th year of alfalfa planting, and reseeding may be needed around the 10th year to prolong the life of alfalfa community. Alfalfa should be planted for no more than 12 consecutive years in the study area for ecological protection.

Genome-wide association analysis reveals novel candidate loci and a gene regulating tiller number in orchardgrass

Tillers are specialized lateral shoots arising from axillary buds at basal nodes, and are also an important agronomic trait that determines the aboveground biomass and grain yield of various gramineous crops. So far, few genes have been reported to control tiller formation and most have been in the annual crop rice (Oryza sativa). Orchardgrass (Dactylis glomerata) is an important perennial forage crop with great economic and ecological value, but its genes regulating tillering have remained largely unknown. In the present study, we used a natural population of 264 global orchardgrass germplasms to determine genes associated with quantitative variation in tiller number through genome-wide association study analysis. A total of 19 putative loci and 55 genes associated with tiller number were thus identified. Additionally, 26 putative differentially expressed genes with tiller number, including DgCYC-C1, were identified by RNA-seq and genome-wide association study analysis. DgCYC-C1 which is involved in cell division, was overexpressed, revealing that DgCYC-C1 positively regulates tiller number. These results provide some new candidate genes or loci for the improvement of tiller number in crops, which might advance new sustainable strategies to meet global crop production challenges.

Are Animals Needed for Food Supply, Efficient Resource Use, and Sustainable Cropping Systems? An Argumentation Analysis Regarding Livestock Farming

It has been argued that livestock farming is necessary to feed a growing population, that it enables efficient use of land and biomass that would otherwise be lost from the food system, that it produces manure that is necessary for crop cultivation, and helps improve the sustainability of cropping systems by inclusion of perennial forage crops in otherwise low-diversity crop rotations. In this paper, we analyze these arguments in favor of livestock farming. Through argumentation analysis based on scientific data, we show that the arguments are either invalid or that their validity is limited to certain circumstances. Without taking into consideration any other potential arguments for livestock farming, or arguments against it, we conclude that the arguments analyzed here cannot in isolation provide justification for more than a small proportion of today’s livestock farming.

Carbon sequestration potential and its main drivers in soils under alfalfa (Medicago sativa L.)

As a perennial forage crop, alfalfa (Medicago sativa L.) has been extensively utilized for the vegetation restoration of degraded soil and provides feedstock for forage. Its high usage can be attributed to its high yield potential and the increasing soil organic carbon (SOC) sequestration of alfalfa cultivation. However, the impact of land conversion to alfalfa on SOC content and its underlying drivers remain unclear. We performed a meta-analysis at the global scale to explore the quantified effects of alfalfa cultivation on SOC content and identify its controlling factors. We employed 1699 pairwise data points from 90 publications based on cropland/abandoned land conversion to alfalfa. Globally, cropland (cropland-alfalfa) and abandoned land (abandoned land-alfalfa) conversion to alfalfa enhanced SOC content by 12.1 % and 13.7 %, respectively. Alfalfa exhibited greater SOC content benefits in the surface soils (0–20 cm) with a lower level of initial SOC (<16 g kg−1), regardless of the land conversion type. Cropland-alfalfa was observed to increase SOC content with fertilization, irrigation, and conventional tillage in the long term (>5 years). Furthermore, abandoned land-alfalfa enhanced SOC content in the absence of alfalfa biomass removal and for longer cultivation durations (>5 years). Boosted regression tree analyses indicated variations in soil properties (75 % for cropland-alfalfa and 65 % for abandoned land-alfalfa) as the primary factors driving changes in SOC content. The dominant drivers were determined as the soil layer (51.6 %), cultivation duration (13.1 %), and initial SOC (12.9 %) for cropland-alfalfa, and initial SOC (43.7 %), soil layer (24.6 %) and cultivation duration (17.1 %) for abandoned land-alfalfa. Land conversion to alfalfa has great potential for SOC sequestration, particularly in low-fertility soils. Therefore, alfalfa cultivation is highly recommended for degraded lands due to its SOC sequestration benefits in vegetation restoration.

Mechanism of action of microRNA166 on nitric oxide in alfalfa (Medicago sativa L.) under drought stress

BackgroundAlfalfa is a perennial forage crop of high importance, but its cultivation is often affected by drought stress. Currently, the investigation of drought-related small RNAs is a popular research topic to uncover plant drought resistance mechanisms. Among these small RNAs, microRNA166 (miR166) is associated with drought in numerous plant species. Initial small RNA sequencing studies have shown that miR166 is highly responsive to exogenous nitric oxide (NO) and drought. Therefore, analyzing the expression of Msa-miR166 under nitric oxide and drought treatment is significant.ResultBioinformatics analysis revealed that the miR166 family is widely distributed among plants, ranging from mosses to eudicots, with significant distribution differences between species. The evolutionary degree of Msa-miR166s is highly similar to that of Barrel medic (Medicago truncatula) and Soybean (Glycine max), but significantly different from the model plant Arabidopsis (Arabidopsis thaliana). It is suggested that there are no significant differences in miR166s within the species, and members of Msa-miR166s can form a typical stem-loop. The lowest level of exogenous nitric oxide was observed in Msa-miR166s under drought stress, followed by individual drought, and the highest level was observed after removing endogenous nitric oxide.ConclusionIn response to short-term drought, Msa-miR166s down-regulate expression in alfalfa (Medicago sativa L.). Exogenous nitric oxide can reduce the expression of Msa-miR166s in response to short-term drought. These findings suggest that Msa-miR166e-5p is responsive to environmental changes. The expression levels of target genes showed an opposite trend to Msa-miR166s, verifying the accuracy of Degradome sequencing in the early stage. This suggests that alfalfa experiences drought stress when regulated by exogenous nitric oxide, targeting HD ZIP-III, FRI, and CoA ligase genes. Additionally, the expression of Msa-miR166s in response to drought stress varies between leaves and roots, indicating spatiotemporal specificity.

Warmer future climate in Canada—implications for winter survival of perennial forage crops

Significant increase in wintertime air temperature, especially the reduced cold extremes under climate change, might be beneficial to the winter survival of perennial crops. However, climate warming could result in less snowfall, reduced snow cover, as well as changes in climate conditions for fall hardening and winter thaws. How these changes might impact the risks of winter damages to overwintering crops, such as perennial forage crops requires a comprehensive assessment for proactively adapting to climate change in the agricultural sector, especially the beef and dairy industries. Based on the most up-to-date climate projections from a set of global climate models, we used a snow model and a suite of agroclimatic indices for perennial forage crops to assess potential changes in the risks of winter injury to perennial forage crops across Canada in the near-term (2030s), the mid-term (2050s), and the distant future (2070s). Our results show that the risk of exposure to extremely low temperatures (daily Tmin ≤ −15 °C) without snow protection is projected to decrease across Canada with improved conditions for fall hardening. However, winter thaws and rainfall are projected to increase, and this would increase the risk of winter injury due to loss of hardiness together with potential soil heaving and ice encasement.

Productivity and economic feasibility of cultivated forage and food crops in the central highlands of Ethiopia

The study was conducted to evaluate the yield performance of improved forage and food crops and to estimate the profitability of fodder and food crops in Holetta and Ejere areas, central highlands of Ethiopia during 2019 and 2020 cropping seasons. The experiment was laid out in randomized complete block design with three replications and evaluated two annual forage crops, two perennial forage crops, and two cereal food crops. Data on herbage dry matter (DM) yield was collected for forage crops while straw and grain yields were measured for food crops. Partial budget analysis was made to evaluate the economic feasibility of forage and food crops production. The result revealed that the herbage DM yield varied (P&amp;lt;0.05) at each location during each production year and combined over years and between the two locations. The straw and grain yields of food crops also varied (P&amp;lt;0.05) between the two production years and locations. The nutritive values of herbage and straw yields of forage and food crops differed (P&amp;lt;0.05) for all measured parameters. The crude protein and in-vitro dry matter digestibility of perennial forage crops were relatively higher than annual forage crops and straw of food crops. The partial budget analysis result indicated that the gross revenue (GR) and net return (NR) obtained from food crops were the highest followed by annual forage crops while the least was recorded from perennial forage crops during the first year of production. However, perennial forage crops produced the higher GR and NR than food crops and annual forage crops in the second year of production. In the second year of production, among the forage crops, Desho grass generated 308, 293, 287, and 232% while Rhodes grass generated 99, 92, 90, and 62% more NR than wheat, sole oat, barley, and oat/vetch mixtures, respectively. The benefit-cost ratio (BCR) of perennial forage crops was the lowest (3.0 for Desho and 1.6 for Rhodes) in the first year of production but the ratio was the highest (17.2 for Desho and 8.6 for Rhodes) in the second year of production. This confirms the better economic feasibility of perennial forage crops as they can be maintained using minimal management cost once they have been established.

Simulated soil water distribution patterns and water use of Alfalfa under different subsurface drip irrigation depths

Alfalfa is one of the major perennial forage crops in California, vital for the livestock industry, and provides environmental benefits to the ecosystem in the state. Information on subsurface drip irrigation (SDI) practices on alfalfa is limited particularly in areas related to drip tape spacings and installation depths and their impacts on topsoil profile wetting patterns and alfalfa productivity. The objective of this study was to compare three different depths of drip lines: 15, 30, and 45 cm on topsoil profile wetting patterns and identify the optimum depth for achieving sustainable management practices for alfalfa production under SDI. Crop water requirements were determined using Tule Technologies system. Volumetric soil water contents from twelve cuts were simulated using HYDRUS-2D. Initial volumetric soil water contents from Watermark sensors were used in the model and measured volumetric soil water distributions were used for hydraulic conductivity calibration. Simulated results showed that there was no significant difference between root water uptake (RWU) among the various drip depths. RWU was 171.6, 170.0, and 168.2 cm at drip line depths of 15, 30, and 45 cm, respectively. Applied irrigation water during the study period was 195.1 cm while rainfall was 4.1 cm. A 10% reduction in topsoil volumetric soil water content was observed for drip lines at 30 cm depth as compared with 15 cm depth, while a 20% reduction in topsoil volumetric soil water content was observed for drip lines at 45 cm depth as compared with 15 cm depth. Drip lines at 30 cm depth are likely the optimal for RWU and free drainage; however, drip lines at 45 cm depth may allow growers to provide additional irrigation events (without increasing the topsoil volumetric soil water content) closer to the harvest date, potentially resulting in higher yield and water use efficiency.

Replenishment of the VIR perennial forage crops collection with samples from a collecting mission in Tambov and Ryazan provinces in 2018

The purpose of the collecting mission was to replenish the collection of perennial forage crops with crop wild relatives (CWR) of interest for breeding purposes, as well as for the subsequent preservation of forage CWR diversity in natural populations. The mission was tasked to conduct a survey of the territory along the middle and lower Tsna river and collect seeds of wild perennial and annual forages. Coordinates of collecting sites were recorded and sites mapped together with the collecting mission route. Two districts of the Tambov and two districts of Ryazan provinces were explored. As a result, 93 seed samples were collected. Out of these, 47 samples were perennial forage grasses, 39 perennial and annual forage legumes, and 7 belonged to other families. The main part of legumes was represented by Medicago species (11 samples of Medicago falcata L., M. varia Mart., M. lupulina L.) and clover (11 samples of Trifolium hybridum L., T. incarnatum L., T. medium L., T. pratensis L., T. repens L.); among the grasses there were Bromopsis inermis (Leyss.) Holub, Poa angustifolia L., Dactylis glomerata L., and Phleum pratense L.

Phenotypic characterization of drought responses in red clover (Trifolium pratense L.).

Red clover (Trifolium pratense) is a protein-rich, short-lived perennial forage crop that can achieve high yields, but suffers increasingly from drought in different cultivation areas. Breeding for increased adaptation to drought is becoming essential, but at this stage it is unclear which traits breeders should target to phenotype responses to drought that allow them to identify the most promising red clover genotypes. In this study, we assessed how prolonged periods of drought affected plant growth in field conditions, and which traits could be used to distinguish better adapted plant material. A diverse panel of 395 red clover accessions was evaluated during two growing seasons. We simulated 6-to-8-week drought periods during two consecutive summers, using mobile rain-out shelters, while an irrigated control field was established in an adjacent parcel. Plant growth was monitored throughout both growing seasons using multiple flights with a drone equipped with RGB and thermal sensors. At various observation moments throughout both growing seasons, we measured canopy cover (CC) and canopy height (CH). The crop water stress index (CWSI) was determined at two moments, during or shortly after the drought event. Manual and UAV-derived measurements for CH were well correlated, indicating that UAV-derived measurements can be reliably used in red clover. In both years, CC, CH and CWSI were affected by drought, with measurable growth reductions by the end of the drought periods, and during the recovery phase. We found that the end of the drought treatment and the recovery phase of approximately 20 days after drought were suitable periods to phenotype drought responses and to distinguish among genotypes. Multifactorial analysis of accession responses revealed interactions of the maturity type with drought responses, which suggests the presence of two independent strategies in red clover: 'drought tolerance' and 'drought recovery'. We further found that a large proportion of the accessions able to perform well under well-watered conditions were also the ones that were less affected by drought. The results of this investigation are interpreted in view of the development of breeding for adaptation to drought in red clover.

Study and evaluation of varieties of non-traditional forage crops in the conditions of the cryolithozone

In the Republic of Sakha (Yakutia), where the main focus of agriculture is animal husbandry, there is a problem of providing cattle with high-quality feed. Currently, the productivity of natural hayfields in Yakutia, due to their irrational use, has decreased from 1.5-1.7 t/ha of hay in the 50s and 60s of the last century to 0.5-0.7 t/ha. Traditional annual and perennial forage crops do not provide the full amount of dry and juicy feed needed. In this regard, research has been conducted on the permafrost floodplain soils of Yakutia to study and search for varieties of non-traditional forage crops that would guarantee a high annual yield of forage mass. The varieties of mogara Altaysky 23, common millet Barnaulskoye 98, Barnaulskoye 18 and Africanskoye K-157 were studied. Experiments have shown that in the conditions of the cryolithozone, the development of mogara plants and common millet plants proceeds slowly and reaches the beginning of flowering phase at the end of the growing season, Africanskoye K-157 millet has more accelerated development and it stops at the beginning of seed maturation. The most leafy millet variety Africanskoye K-157 - (160.4 cm2/plant) provides the highest productivity of green mass (39.8 t/ha); the studied varieties of non-traditional forage crops are rich in protein content (12.5-14.3%), feed units (0.50-0.55 g per 1 kg), exchange energy for ruminants animals (7.1-7.4 MJ/kg).

Quantitative proteomic analysis of the role of miRNA156 in alfalfa under drought stress

Alfalfa is the most produced perennial forage crop in Canada. Drought stress is a major form of abiotic stress, affecting its productivity and annual yield. A small RNA, miR156, plays a major role in drought tolerance by downregulating downstream SPL genes, but its effects at the proteome level are unknown. In this study, the protein level perturbations of miR156 overexpression (A8) and empty vector (EV) control genotypes were compared under drought stress. Using label-free quantification, 3000 protein groups were identified, of which 68 were upregulated in A8 and 84 were downregulated relative to EV under control conditions. Conversely, under drought stress, 610 proteins were upregulated and only 52 proteins were downregulated in A8 relative to EV. Functional analysis using PlantRegMap showed that the enriched proteins are likely involved in biological and molecular processes including antioxidant response, response to stress, signal transduction and biosynthesis of secondary metabolites. These proteins/pathways might be involved in the enhancement of drought stress tolerance mediated by miR156. Protein groups related to signaling, such as MAP kinase, calcium-dependent protein kinase, protein phosphatase 2 C, and transcriptional regulators including bZIP and zinc finger proteins were found to be differentially expressed when a search was conducted against a drought stress gene database. The proteomic dataset was validated by immunoblotting of selected proteins. The results of this study provide a better understanding and insight into the role of miR156 in drought stress tolerance in alfalfa at the proteomic level.

N2 Use in Perennial Swards Intercropped with Young Poplars, Clone I-214 (Populus × euramericana (Dode) Guinier), in the Mediterranean Area under Rainfed Conditions

Intercropping perennial legumes with trees can reduce Nitrogen (N) losses, due to the high amount of N accumulated in stable forms in the soil and permanent soil cover during the whole year. Although N cycling improvement in mature agroforestry systems (AFS) was well documented, there is a lack of knowledge regarding systems in transition to AF. In this work, we studied the association of two perennial forage crops, namely ryegrass (Lolium multiflorum Lam.) and sulla (Hedysarum coronarium L.), with 1-year old poplars, to evaluate: (i) the agronomic performance of sulla and ryegrass with vs. without intercropped poplar trees; (ii) the N-fixing ability of sulla in association with trees; (iii) the N transfer effect from sulla and growth promoting effect on poplar; and finally (iv) the nitrate leaching reduction due to the presence of poplar trees associated to forage crops. The layout was arranged in a two-factor randomized complete blocks design (RCB) with three replicates. The first factor tested (crop species) implied two different swards, namely sulla and ryegrass. The second factor (cropping system) included two different systems: PAST i.e., a pastoral system without trees, and SIPAST, i.e., a silvo-pastoral system with one poplar tree row beside the sward. Sulla resulted more productive than ryegrass when associated with trees (+35%). No clear trend was observed about the tree influence on N-fixation in sulla, but the amount of N fixed resulted higher in in sulla grown in the SIPAST near the trees (+35%). Poplar plants, even in the first year after planting, resulted effective yet in reducing the nitrate flux from the crops towards ditches. Further investigations are needed to study other swards in young AF and better understand the N dynamics; in particular, it could be worth to assess the nutrient flux in the soil solution.

Simulation of alfalfa yield with AquaCrop

The AquaCrop simulation model, originally designed for annual crops, is expanded here to simulate alfalfa, a perennial forage crop. A new routine was added to the model to mimic the assimilate partitioning between above and below-ground plant parts to account for the utilization of reserves in Spring and for their storage in the Fall. The simulation of the transfer of assimilates requires only three extra crop parameters which makes the model also easy to calibrate. To evaluate the model, yield data collected in Louvain-La-Neuve (Belgium), Isparta (Turkey), and Ottawa (Canada) for different alfalfa cultivars, various years and field and irrigation management strategies were used. To assess the accuracy and robustness of the simple assimilate remobilization process, simulations were run for the three different environments with a common set of crop parameters which were parameterized. The dispersion between the observed and simulated cumulative dry above-ground biomass during the growing cycle was small (r² = 0.97; nRMSE = 11%; Nash-Sutcliffe model EF = 0.97), and a systematic over- or underestimation by the model was not observed (Willmott’s index of agreement, d = 0.99). When evaluating the goodness of fit of the 81 individual harvest events, the results were still very satisfactory although the nRMSE doubled. The simulations indicated that the AquaCrop model adapted to perennial crops and with a novel storage-remobilization routine, could predict well alfalfa yields in various climates and environments, with and without water and fertility stress, and for three different alfalfa cultivars.

SimET: An open-source tool for estimating crop evapotranspiration and soil water balance for plants with multiple growth cycles

Accurate estimation of crop evapotranspiration (ETc) and soil water balance, which is vital for optimizing water management strategy in crop production, can be performed by simulation. But existing software has many deficiencies, including complex operation, limited scalability, lack of batch processing, and a single ETc model. Here we present simET, an open-source software package written in the R programming language. Many concepts involved in crop ETc simulation are condensed into functions in the package. It includes three widely used crop ETc models built on these functions: the single-crop coefficient, double-crop coefficient, and Shuttleworth–Wallace models, along with tools for preparing model data and comparing estimates. SimET supports ETc simulation in crops with repeated growth cycles such as alfalfa, a perennial forage crop that is cut multiple times annually.

Aerial and ground-based phenotyping of an alfalfa diversity panel to assess adaptation to a prolonged drought period in a Mediterranean environment of central Chile

Climate change is one of the biggest challenges facing food production worldwide, particularly in Mediterranean climate regions where rainfall has been decreasing and temperature increasing. Alfalfa is a perennial forage crop that could play an important role in increasing the resilience and sustainability of rainfed production systems in these environments. In this study, we tested how a prolonged drought period of 5–6 months in a Mediterranean environment of central Chile affects the plant persistence and productivity of an alfalfa diversity panel of 69 landraces, cultivars, and diverse pre-breeding populations (hereafter accessions) from Kazakhstan, Azerbaijan, Spain, Australia, USA, and Chile, with putative drought tolerance. The objectives were i) to evaluate the phenotypic variability in plant survival and productivity among the alfalfa diversity panel, under rainfed and with supplemental irrigation, in a Mediterranean environment; and ii) to study the use of an NDVI sensor, and RGB and thermal cameras for field phenotyping and evaluation of canopy traits, such as leaf area index (LAI) and forage yield (FY). Results showed large phenotypic variability for plant survival after the three drought periods, ranging from 30 % to 76 % under rainfed conditions and from 48 % to 90 % with supplementary irrigation. The FY during winter was significantly different between cultivars, with more than 4 Mg ha-1 per year in some accessions. The average FY for three growing seasons (2018–2020) ranged between 2.26 and 10.80 Mg ha-1 under rainfed and 3.92–11.14 Mg ha-1 per year with supplementary irrigation. Among the most productive accessions under both water regimes were two populations of the Medicago arborea x sativa hybrid (AF3448 and AF3347), cultivars Genesis and Venus, and the landraces Aragon from Spain and Alta Sierra 2 from Chile. The normalized difference vegetation index (NDVI) showed exponential and positive relationships with the leaf area index (LAI) and FY. RGB images were obtained at 60 cm above the top of the canopy with a digital camera and at 30 m using a drone. The RGB indices “intensity”, a* and greener area obtained from images taken at 60 cm above the top of the canopy, were highly correlated (r = 0.76 – 0.98; P < 0.0001) with the NDVI and FY, under rainfed and with supplementary irrigation in 2019. The RGB indices “saturation”, a* and u* obtained from a drone at 30 m, were also highly correlated (r > 0.73 – 0.94; P < 0.0001) with the NDVI and FY of accessions growing under both water regimens in 2020. The canopy temperature (CT) obtained from thermal images from a drone was higher under the rainfed regime. The stress degree day (SDD), defined as the difference between canopy temperature (Tc) and air temperature (Ta) was negatively related to FY. Under the rainfed regimen, the population AF3348 and cultivars Genesis and Aragon exhibited the lowest SDD and the highest FY.

Effects of soil amendments on hairy vetch no‐till interseeded into a hayfield

AbstractIncreasing the abundance of legumes in mixed pasture and hayfield stands can improve forage nutritional quality and nutrient cycling; however, establishing legumes can be difficult, especially without tillage or chemical suppression of existing vegetation. Soil amendments that reduce the competitiveness of the existing plant community or improve the vigor of interseeded legumes could reduce the need for more intensive management practices at the time of interseeding. We compared a range of commercially available soil amendments for their effects on the no‐till establishment of hairy vetch (Vicia villosa Roth) interseeded into an existing sod. Amendment treatments were applied in September and included wood ash, biochar, lime, and K applied at different rates, and unamended tilled and untilled treatments as controls. Hairy vetch was no‐till interseeded immediately after treatment application and biomass was measured the subsequent June. Results were consistent across the two site‐years and indicated that an intermediate rate of wood ash (8967 kg ha−1) increased hairy vetch biomass in the spring by 8.5 and 12.4 times compared to the tilled and unamended controls, respectively. We used nonparametric multiplicative regression (NPMR) to explore the relationship between soil physical and chemical properties and hairy vetch biomass across a range of wood ash application rates. We found that soil K alone explained 42% of the variability in hairy vetch biomass. This research suggests that wood ash soil amendments may improve the chances of successfully interseeding legumes into perennial forage crops without the use of herbicide or tillage to suppress the existing plant community.

Оценка генетического разнообразия популяций Medicago varia Mart. отобранных для селекции в условиях Республики Башкортостан методом SSR-анализа

Medicago varia Mart. (bastard alfalfa) is a highly productive, protein-rich, perennial forage crop, well adapted to the conditions of the Southern Urals and Cis-Urals. In the Republic of Bashkortostan, the breeding of alfalfa is carried out at the Bashkir Scientific Research Institute of Agriculture of the UFRC RAS and the experimental station “Ufimskaya”. To assess the genetic polymorphism of the initial seed material, accurately identify and certify alfalfa varieties, the SSR analysis method can be used, which consists of PCR analysis of the sizes of loci containing microsatellite repeats. Most alfalfa SSR markers have been developed for the model object Medicago truncatula Gaertn. (truncated alfalfa), several studies on the SSR loci of Medicago sativa L (common alfalfa) have been published. For genetic analysis of bastard alfalfa, it is proposed to use the same SSR markers, but how effective they will be on domestic varieties of this species remains unknown. The purpose of this study was to test SSR primers for 10 microsatellite loci on populations of bastard alfalfa, which are in breeding study at the Republic of Bashkortostan. For the study, four samples of M. varia were used: variety Chishminskaya 131, populations Skorospelaya 9, S 3-6, and S 3-8. Analysis of the molecular genetic polymorphism of these M. varia samples using the SSR-PCR method allowed us to obtain data on the allelic composition of the microsatellite loci MsEST53, MSE265, MSE562, MSE486, MSE195, MSE590, MSE323, MsEST9, MSE470, MSE276. The most effective for genetic certification of varieties and populations of this crop were the SSR markers MsEST53, MSE265, MSE562, MSE486, MSE195, MSE590, MsEST9, which gave the largest number of polymorphic DNA fragments according to the results of PCR and polyacrylamide gel electrophoresis, making it possible to distinguish all four samples, and were also characterized by similar primer annealing temperatures and non-overlapping allelic ranges, which makes it theoretically possible to use them in multiplex PCR. The highly variable SSR markers identified during the study can be used to create test systems for accurate identification and certification of varieties, as well as for assessing the genetic polymorphism of M. varia samples.

Correlation and path coefficient analyses of dry weight yield components in the common sainfoin (Onobrychis viciifolia Scop.)

Sainfoin (Onobrychis viciifolia Scop.) is a perennial forage crop with desirable forage properties adapted to temperate climate conditions. The purpose of this research was to study the phenotypic correlation coefficients between dry forage yield and some morphological traits, and to identify the direct and indirect effects of the associated traits. Thus, 32 ecotypes (landraces) were assessed in the randomized complete block design layout with four replications. Positive and statistically significant correlations were determined between total dry weight (TDW) and all measured traits except for internode length (IL) [r=0.29, P&gt;0.05]. Regarding the variance inflation factor (VIF) as a multicollinearity statistic, number of nodes per main stem (VIF=1407.4) and number of internodes per main stem (VIF=1371.6) were removed from the analysis. Path coefficient analyses indicated that number of leaflets per leaf (NLL) [0.59 direct effect], height of the longest stem (HLS) [0.42 direct effect], and dry weight/fresh weight ratio (DFR) [0.27 direct effect] were influenced by TDW as a first-order trait. Five traits considered secondary or tertiary traits affected TDW - number of stems per area (NPA), number of stems per plant (NSP), number of leaves per stem (LS), length of inflorescence (LI) and stem weight/leaf weight ratio (SLR). The importance of main stem properties such as length or height, number of leaves, and number of leaflets can be used for selection in breeding programs aimed at improving common sainfoin forage yield under semi-arid conditions.