Biochar derived from olive oil pomace mitigates salt stress on seedling growth of forage pea.

Studies are being conducted to develop strategies to reduce the adverse effects of salinity stress. In the present study, it was aimed to determine the interactive effects of salinity stress with biochar on plant growth-the physiological and biochemical attributes of forage peas (Pisum sativum ssp. arvense L.). Salt applications were carried out with irrigation water at concentrations of 0, 25, 50, 75, and 100 mM NaCl. The experiment was conducted using a randomized complete block design with three applications [control: 0 (B0), 2.5% biochar (B1), and 5% biochar (B2)], five salt doses [0 (S0), 25 (S1), 50 (S2), 75 (S3), and 100 (S4) mM NaCl], and three replications, arranged in a 3 × 5 factorial arrangement. In the salt-stressed environment, the highest plant height (18.75 cm) and stem diameter (1.71 mm) in forage pea seedlings were obtained with the application of B1. The root fresh (0.59 g/plant) and dry weight (0.36 g/plant) were determined to be the highest in the B1 application, both in non-saline and saline environments. A decrease in plant chlorophyll content in forage pea plants was observed parallel to the increasing salt levels. Specifically, lower H2O2, MDA, and proline content were determined at all salt levels with biochar applications, while in the B0 application these values were recorded at the highest levels. Furthermore, in the study, it was observed that the CAT, POD, and SOD enzyme activities were at their lowest levels at all salt levels with the biochar application, while in the B0 application, these values were determined to be at the highest levels. There was a significant decrease in plant mineral content, excluding Cl and Na, parallel to the increasing salt levels. The findings of the study indicate that biochar amendment can enhance forage peas' growth by modulating the plant physiology and biochemistry under salt stress. Considering the plant growth parameters, no significant difference was detected between 2.5% and 5% biochar application. Therefore, application of 2.5 biochar may be recommended.

Exploring the Water-Soil-Crop Dynamic Process and Water Use Efficiency of Typical Irrigation Units in the Agro-Pastoral Ecotone of Northern China.

Groundwater resources serve as the primary source of water in the agro-pastoral ecotone of northern China, where scarcity of water resources constrains the development of agriculture and animal husbandry. As a typical rainfed agricultural area, the agro-pastoral ecotone in Inner Mongolia is entirely dependent on groundwater for agricultural irrigation. Due to the substantial groundwater consumption of irrigated farmland, groundwater levels have been progressively declining. To obtain a sustainable irrigation pattern that significantly conserves water, this study faces the challenge of unclear water transport relationships among water, soil, and crops, undefined water cycle mechanism in typical irrigation units, and water use efficiency, which was not assessed. Therefore, this paper, based on in situ experimental observations and daily meteorological data in 2022-2023, utilized the DSSAT model to explore the growth processes of potato, oat, alfalfa, and sunflower, the soil water dynamics, the water balance, and water use efficiency, analyzed over a typical irrigation area. The results indicated that the simulation accuracy of the DSSAT model was ARE < 10%, nRMSE/% < 10%, and R2 ≥ 0.85. The consumption of the soil moisture during the rapid growth stage for the potatoes, oats, alfalfa, and sunflower was 7-13% more than that during the other periods, and the yield was 67,170, 3345, 6529, and 4020 kg/ha, respectively. The soil evaporation of oat, potato, alfalfa, and sunflower accounted for 18-22%, 78-82%; 57-68%, and 32-43%, and transpiration accounted for 40-44%, 56-60%, 45-47%, and 53-55% of ETa (333.8 mm-369.2 mm, 375.2 mm-414.2 mm, 415.7 mm-453.7 mm, and 355.0 mm-385.6 mm), respectively. It was advised that irrigation water could be appropriately reduced to decrease ineffective water consumption. The water use efficiency and irrigation water use efficiency for potatoes was at the maximum amount, ranging from 16.22 to 16.62 kg/m3 and 8.61 to 10.81 kg/m3, respectively, followed by alfalfa, sunflowers, and oats. For the perspective of water productivity, it was recommended that potatoes could be extensively cultivated, alfalfa planted appropriately, and oats and sunflowers planted less. The findings of this study provided a theoretical basis for efficient water resource use in the agro-pastoral ecotone of Northern China.

Virulent Fusarium isolates with diverse morphologies show similar invasion and colonization strategies in alfalfa.

Root rot is a major disease that causes decline of alfalfa production, and Fusarium is a major pathogen associated with root rot. In this study, 13 Fusarium isolates were obtained from alfalfa with root rot in Gansu Province, the major alfalfa production region in China. The isolates were characterized by molecular genotyping (ITS, TEF 1-α and RPB2 fragments) and identified as six species, which included the F. acuminatum, F. incarnatum, F. oxysporum, F. proliferatum, F. redolens, and F. solani. We found that their morphology varied significantly at both the macro- and micro-levels, even for those from the same species. We developed a low cost and fast pathogenicity test and revealed that all isolates were pathogenic to alfalfa with typical root rot symptoms such as leaf yellowing and brown lesions on the root and stem. However, the virulence of the isolates differed. We also found that the conidia of all isolates germinated as early as 24 hours post inoculation (hpi), while hyphae colonized the root extensively and invaded the xylem vessel by 48 hpi. Together our results reveal that different virulent Fusarium isolates use a similar invasion strategy in alfalfa. This natural plant-fungus pathosystem is intriguing and warrants further examination, particularly with regard to efforts aimed at mitigating the impact of multiple similar vascular pathogens on infected alfalfa plants.

Zeolite application mitigates NH3 and N2O emissions from pig slurry-applied field and improves nitrogen use efficiency in Italian ryegrass-maize crop rotation system for forage production.

The present study aimed to assess the efficiency of zeolite in mitigating the nitrogen (N) losses through ammonia (NH3) and nitrous oxide (N2O) emissions from pig slurry (PS) applied to Italian ryegrass (IRG)-maize fields under a crop rotation system and the consequent effect on nitrogen use efficiency (NUE) for forage production. PS was applied at rates of 150 and 200 kg N ha-1 for the IRG and maize growing seasons, respectively, with or without zeolite. Soil mineral N content and NH3 and N2O emissions were measured periodically throughout the year-round cultivation of IRG and maize. Forage yield and nutritional composition were also analyzed at the harvest time of each crop. The PS with/without zeolite application effects were interpreted by comparison with those obtained for the negative control (no-N fertilization). Soil ammonium (NH4+) content in the PS-applied plots sharply increased within the first week, then progressively decreased in both the IRG and maize growing seasons. Soil NH4+ contents in the zeolite-amended plots were higher compared to the treatment without zeolite except for the first 1 or 2 weeks after PS application when soil nitrate (NO3-) contents significantly decreased. The increase in soil NH4+ content as affected by zeolite application was more distinct in the maize growing season than in the IRG growing season. NH3 emission was predominant at the early 2 weeks after PS application. Zeolite application reduced the cumulative emission of NH3 from PS by 16.7% and 24.4% and that of N2O by 15.6% and 31.5% in the IRG growing and maize growing seasons, respectively. NUE for dry matter (DM) and total digestible nutrients (TDN) production significantly improved in annual yield basis of the IRG-maize cropping. Zeolite application in PS-applied field may represent effective management in mitigating N losses through odorous NH3 and greenhouse gas (N2O) emissions, thereby improving NUE forage production.

Fostering in situ conservation of wild relatives of forage crops.

Most plant conservation strategies generally overlook the intra-specific genetic diversity of crop gene pools. Focusing on forage crops and their wild relatives, we present a novel approach to address the conservation of these species on meadows. Two-thirds of Swiss agricultural land is green land, mostly used for forage purposes, and their genetic diversity is being threatened. We focused here on eight plant associations gathering at least 18 taxa considered priority crop wild relatives of forage crops. Since 2020, about 1,217 high-quality surfaces (representing 1,566 hectares) nationwide have been integrated into an innovative auction-based policy instrument dedicated to conserving these populations. Here, we report the benefits and hurdles of implementing this bottom-up approach and try to estimate the quality of conservation of the forage plants' CWR gene pool. Although we focus on the Swiss case, our approach to in situ conservation offers opportunities to effectively guide conservation in other contexts. We also discuss possible ways to improve CWR conservation policy, particularly the need to better consider the populations and habitat levels.

Alternative ground covers and strip-tilling in CBD hemp production.

OBJECTIVE: Little research has been done on managing soil health for large-scale, outdoor hemp production, contributing to the possible overuse of black plastic for weed suppression. Our experiment aimed to understand the performance of alternative ground covers including forage crops and hay as well as a less disruptive tilling method called strip-tilling compared to black plastic. RESULTS: Yield and soil health data were taken from three experimental plantings from two different outdoor CBD hemp farms in Vermont, USA. We find that hay may be a competitive alternative to black plastic in terms of producing heavier plants. Our research also found that clover seed and hay are both more cost-effective options than black plastic which may sway some farmers to adopt these alternative ground cover options.

Agronomic biofortification of forage crops with zinc and copper for enhancing nutritive potential: a systematic review.

Many developing countries are facing a silent increase in deficiency of micronutrients in forage crops that results in decreased levels of essential nutrients in animals. Micronutrients are essential not only for basic metabolic processes of forage crops but also for sustaining animal health. Forage productivity and quality are severely affected by soil micronutrients deficiencies, especially zinc and copper. This review summarizes the literature highlighting the significance of different methodologies used to increase the biomass and quality of forage so as to enhance the micronutrient content of the forage crops through biofortification. Biofortification is a promising and sustainable agriculture-based strategy to reduce micronutrient deficiency in crops. The experiments and trials conducted at different locations of the world showed that copper and zinc concentrations in animal fodders can be enhanced through the process of foliar application. Additionally, agronomic biofortification showed more promising results, and thus is an outstanding, fast, and cost-effective technique for the immediate enrichment of forage in order to overcome malnutrition in animals. © 2022 Society of Chemical Industry.

Genetic Diversity, Analysis of Some Agro-Morphological and Quality Traits and Utilization of Plant Resources of Alfalfa.

Alfalfa (Medicago sativa L.) is one of the most important perennial forage crops to build effective diets for livestock producers. Forage crop improvement depends largely on the availability of diverse germplasms and their efficient utilization. The present investigation was conducted at Ismailia Agricultural Research Station to assess twenty-one alfalfa genotypes for yield components, forage yield and quality traits during 2019/2020 and 2020/2021. The genotypes were evaluated in field experiments with three replicates and a randomized complete block design, using analysis of variance, estimate of genetic variability, estimate of broad sense heritability (hb2) and cluster analysis to identify the inter relationships among the studied genotypes as well as principal component analysis (PCA) to explain the majority of the total variation. Significant differences were found among genotypes for all studied traits. The general mean of the studied traits was higher in the second year than the first year. Moreover, the combined analysis showed highly significant differences between the two years, genotypes and the year × gen. interaction for the traits studied. The genotype F18 recorded the highest values for plant height, number of tiller/m2, total fresh yield and total dry yield, while, the genotype F49 ranked first for leaf/stem ratio. The results showed highly significant variation among the studied genotypes for crude protein %, crude fiber % and ash %. Data revealed that the genotypes P13 and P5 showed the highest values for crude protein %, whereas, the genotype F18 recorded the highest values for crude fiber % and ash content. The results revealed high estimates of genotypic coefficient and phenotypic coefficient of variation (GCV% and PCV%) with high hb2, indicating the presence of genetic variability and effective potential selection for these traits. The cluster analysis exhibited considerable genetic diversity among the genotypes, which classified the twenty one genotypes of alfalfa into five sub-clusters. The genotypes F18, F49, K75, S35, P20, P5 and P13 recorded the highest values for all studied traits compared with other clusters. Furthermore, the PC analysis grouped the studied genotypes into groups and remained scattered in all four quadrants based on all studied traits. Ultimately, superior genotypes were identified can be utilized for crop improvement in future breeding schemes.

Investigation of genetic polymorphism of Russian rape and turnip rape varieties using SSR and SRAP markers.

Rapeseed (Brassica napus L.) and turnip rape (B. rapa L. subsp. campestris (L.)) are important agricultural plants widely used for food, fodder and technical purposes and as green manure. Over the past decades, a large number of perspective varieties that are being currently cultivated in every region of Russia have been developed. To increase the breeding eff iciency and facilitate the seed production, modern molecular-genetic techniques should be introduced as means to estimate species and varietal diversity. The objective of the presented research study was to investigate DNA polymorphism of the rapeseed and turnip rape varieties developed at Federal Williams Research Center of Forage Production and Agroecology and detect informative markers for varietal identif ication and genetic certif ication. To genotype 18 gDNA samples, 42 and 25 combinations of respective SSR and SRAP primers were used. The results obtained demonstrate that SRAP markers were more effective for polymorphism analysis: 36 % of the tested markers revealed genetic polymorphism compared with only 16.7 % of microsatellite loci. Molecular markers to detect differences at interspecif ic and intervarietal levels have also been found. For the investigated set, such microsatellite loci as Na12A02, Ni2C12, Ni02-D08a, Ra02-E01, Ni03H07а and SRAP-marker combinations as F13-R9, Me4- R7, F11-Em2, F10-R7, F9-Em2 and F9-R8 proved to be informative. Application of the two marker techniques made it possible to detect a higher level of DNA polymorphism in plants of different types (spring and winter varieties) if compared against the intervarietal differences within a species or a group. According to Nei's genetic diversity index, in the cluster of winter rapeseed, VIK 2 and Gorizont varieties had the longest genetic distance, and in the spring cluster, these were Novosel and Veles. A high level of similarity was found between Vikros and Bizon winter rapeseed varieties. The results obtained have a high practical value for varietal specif ication of seed material and genetic certif ication of rapeseed and turnip rape varieties.

Multivariate analysis of accumulation and critical risk analysis of potentially hazardous elements in forage crops.

Potentially hazardous element (PHE) contamination of aquifers is an issue of global concern, as this not only affects soil and plants but also exerts a negative impact on livestock. The current study assessed the extent of PHE (cadmium, copper, nickel, and lead) contamination of groundwater, soil, and forage crops in Shorkot, Punjab, Pakistan. Low concentrations of PHEs, particularly Cd and Cu, were found in drinking water which remained below detection limits. The concentrations of Ni and Pb in water samples were 0.1 and 0.06 mg L-1, respectively. Calculated risk indices showed that there was a high carcinogenic and non-carcinogenic risk to livestock (sheep and cow/buffalo) from the ingestion of Ni- and Pb-contaminated water. Soil irrigation with contaminated water resulted in PHE accumulation (Cd: 0.4 mg kg-1, Cu: 16.8 mg kg-1, Ni: 17.6 mg kg-1, Pb: 7.7 mg kg-1) in soil and transfer to forage crops. The potential impact of PHE contamination of the groundwater on fodder plants was estimated for animal health by calculating the average daily dose (ADD), the hazard quotient (HQ), and the cancer risk (CR). While none of the PHEs in forage plants showed any carcinogenic or non-carcinogenic risk to livestock, a high exposure risk occurred from contaminated water (HQ: 12.9, CR: 0.02). This study provides baseline data for future research on the risks of PHE accumulation in livestock and their food products. Moreover, future research is warranted to fully understand the transfer of PHEs from livestock products to humans.

Annual protein yield and extractable protein potentials in three legumes and two grasses.

BACKGROUND: New protein sources with low environmental and climatic impact are needed. Perennial crops show advantages as compared to annual crops and the upcoming biorefinery technology can extract proteins from the perennial biomass for protein concentrate production. The search for best-suited biomass crops needs to include harvest during the full growing season to support economic viability of biorefinery plants. Here we examined two grasses under increasing N fertilizer regime (175, 350 and 525 kg N ha-1 ) and three legumes, subject to a four-cut strategy. The well-defined Cornell Net Carbohydrate and Protein System (CNCPS) was used to estimate potential extractable protein. A key, previously presented in the literature, was applied in order to translate the CNCPS results into potential extracted protein concentrate. RESULTS: Crude protein (CP) yield per hectare was highest in red clover in 2015 (2907 kg CP ha-1 ) and the fertilized (525 kg N ha-1 ) tall fescue in 2016 (2435 kg CP ha-1 ). When translating the numbers into potential extraction of protein concentrate, the red clover had the highest protein concentrate yield per hectare in 2015 (835 kg CP ha-1 ) and lucerne in 2016 (803 kg CP ha-1 ). CONCLUSION: The results revealed that the entire season needs attention for optimization and not only the first cut, since both CP yields and quality peaks in different cuts across the five species and 2 years. Further knowledge of CP yield responses to field management and species mixtures are needed in order to advise farmers on the optimal crop for biorefining. © 2021 Society of Chemical Industry.

Feeding Behavior and Fruiting Form Damage by Bollworm (Lepidoptera: Noctuidae) in Bt Cotton.

Bt technologies have played a major role in the control of bollworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), in cotton. Variation in expression levels among varieties and plant parts, along with selection pressure on bollworm populations, has led to the development of resistance to some Bt proteins. Trials were conducted to evaluate how cotton varieties expressing different Bt proteins affect bollworm larval behavior and their damage in flowering cotton. Differences in larval recovery were observed among cotton varieties at 3 d with 3-gene Bt cotton having the lowest recovery and non-Bt cotton having the greatest recovery. Loss of bloom tags and abscission of small bolls at the site of infestation affected bollworm larval recovery among varieties. Day after infestation was the main factor that affected bollworm movement across all varieties. Number of total damaged fruiting forms by an individual bollworm larva was different among all varieties. Overall, flower bud (square) and fruit (boll) damage by an individual larva was lower on 3-gene cotton than 2-gene cotton and non-Bt cotton. An individual larva damaged fewer squares on 2-gene cotton than non-Bt cotton, but boll damage from bollworm was similar among 2-gene cotton and non-Bt cotton. The level of square and boll damage in 2-gene cotton has increased compared to previous research further supporting the occurrence of bollworm resistance to Cry proteins. The 3-gene cotton containing the Vip3A gene experienced low levels of damage and survival. These results will be important for improving management recommendations of bollworm in Bt cotton technologies.

Is Hay for the Birds? Investigating Landowner Willingness to Time Hay Harvests for Grassland Bird Conservation.

Birds in agricultural environments have exhibited steep global population declines in recent decades, and effective conservation strategies targeting their populations are urgently needed. In grasslands used for hay production, breeding birds' nest success improves substantially if hay harvests are delayed until after mid-July. However, few studies have investigated private hay producers' willingness to alter their harvesting practices, which is a critical factor for bird conservation where most land is privately owned, such as in the North American Great Plains. We surveyed Nebraska hay producers to examine whether livestock production, wildlife knowledge, and hunting activity affects their willingness to alter haying practices for bird conservation. The majority (60%) of respondents expressed willingness to delay harvesting hay to allow birds time to nest successfully. Livestock producers and those more knowledgeable about wildlife were more willing to delay hay harvests, whereas active hunters were less willing to do so. Our findings suggest that a majority of private producers show a high potential for engaging in grassland bird conservation activities. Landowners' willingness to participate in bird conservation programs and actions could be further encouraged through extension and education efforts connecting hay producers with information, support, and funding for bird conservation.

Real-time monitoring of rhizosphere nitrate fluctuations under crops following defoliation.

BACKGROUND: Management regime can hugely influence the efficiency of crop production but measuring real-time below-ground responses is difficult. The combination of fertiliser application and mowing or grazing may have a major impact on roots and on the soil nutrient profile and leaching. RESULTS: A novel approach was developed using low-cost ion-selective sensors to track nitrate (NO3-) movement through soil column profiles sown with the forage crops, Lolium perenne and Medicago sativa. Applications of fertiliser, defoliation of crops and intercropping of the grass and the legume were tested. Sensor measurements were compared with conventional testing of lysimeter and leachate samples. There was little leaching of NO3- through soil profiles with current management practices, as monitored by both methods. After defoliation, the measurements detected a striking increase in soil NO3- in the middle of the column where the greatest density of roots was found. This phenomenon was not detected when no NO3- was applied, and when there was no defoliation, or during intercropping with Medicago. CONCLUSION: Mowing or grazing may increase rhizodeposition of carbon that stimulates soil mineralization to release NO3- that is acquired by roots without leaching from the profile. The soil columns and sensors provided a dynamic insight into rhizosphere responses to changes in above-ground management practices.

Fulvic acid increases forage legume growth inducing preferential up-regulation of nodulation and signalling-related genes.

The use of potential biostimulants is of broad interest in plant science for improving yields. The application of a humic derivative called fulvic acid (FA) may improve forage crop production. FA is an uncharacterized mixture of chemicals and, although it has been reported to increase growth parameters in many species including legumes, its mode of action remains unclear. Previous studies of the action of FA have lacked appropriate controls, and few have included field trials. Here we report yield increases due to FA application in three European Medicago sativa cultivars, in studies which include the appropriate nutritional controls which hitherto have not been used. No significant growth stimulation was seen after FA treatment in grass species in this study at the treatment rate tested. Direct application to bacteria increased Rhizobium growth and, in M. sativa trials, root nodulation was stimulated. RNA transcriptional analysis of FA-treated plants revealed up-regulation of many important early nodulation signalling genes after only 3 d. Experiments in plate, glasshouse, and field environments showed yield increases, providing substantial evidence for the use of FA to benefit M. sativa forage production.

Crop diversification and saline water irrigation as potential strategies to save freshwater resources and reclamation of marginal soils-a review.

Feeding 9 billion by 2050 is one of major challenges for researchers. Use of diversified crops, nonconventional water resources and rehabilitation of marginal lands are alternate options to produce more food to face climate change projections. Adaptation to climate change through climate smart agriculture practices, agroecology activities, and crop-based management packages can help transform the marginal lands from environmental burdens into productive and economic blocks. This review discusses the recent advancements on specialty group of alternate crops (oil seeds, legumes, cereals, medicinal, lignocellulose, and fruit crops) which can adapt in the marginal environments. Availability of alternate water resources (saline water, treated wastewater) for irrigation cannot be omitted. Crop diversification systems involving drought and salt-tolerant crops are likely to be the key to future agricultural and economic growth in the regions where salt-affected soils exist and/or saline aquifers are pumped for irrigation. These systems may tackle three main tasks: sustainable management of land resources and enhancement of per unit productivity; intensification of agroecological practices to increase soil fertility; and improving productivity of marginal lands for diversified climate smart crops. This review explores various aspects of marginal lands and selection of tolerant crop genotypes, crop diversification, and agroecological practices to maximize benefits.

Status and use of pesticides in forage crops in India.

The Indian livestock population is huge. Most (99%) of the livestock owners still follow traditional animal husbandry practices and graze their livestock, especially small ruminants, on natural pastures where no pesticides are used. In order to feed the ever-increasing livestock population, efforts are being made to increase quality fodder productivity from limited land resources. In such situations, pesticides play an important role by minimizing the loss of green fodder due to disease and pest attack. In countries such as Canada, Israel, the UK, and other European countries, pesticides have been registered for forage crops; in India, however, although pesticides have been registered for cultivable grain, horticultural and cash crops, etc., there are no registration guidelines or authenticated information regarding pesticide use with regard to forage crops. Hence, there is a need to take necessary steps in this direction, keeping in view the importance of fodder and livestock in the country. In this review, detailed aspects of the status and use of pesticides in forage crops in India are discussed.

Forage Legumes as Sources of Bioactive Phytoestrogens for Use in Pharmaceutics: A Review.

BACKGROUND: Alfalfa and red clover are the most widespread and most important perennial legumes, primarily used as a high-quality feed for livestock. Both alfalfa and red clover, as well as some other plant species from Fabaceae family, are a rich natural source of phytoestrogens, nonsteroidal compounds with an estrogenic activity whose beneficial effects in the prevention and treatment of many diseases are demonstrated in numerous scientific studies. OBJECTIVES: Nowadays, various herbal preparations are present on the world market and their use is constantly increasing, as well as the growing demands of consumers for environmentally sound and health-safe production of plant species used as sources of active substances. Because of their widespread distribution, the possibility of organic breeding, and also significant increases in surface area under genetically modified crops in most EU countries, alfalfa and red clover have become more interesting alternative sources of phytoestrogens. The most common phytoestrogens in these forage legumes are genistein, daidzein, glycitein, formononetin, biochanin, coumestrol, kaempferol and apigenin. The content of these substances is significantly influenced by a number of factors including genotype, environment, production technology, plant maturity stage, and individual plant parts. CONCLUSION: Available evidence suggests that forage legumes represent high promising sources of health-promoting phytoestrogens. Due to numerous favorable features, they can find commercial application in different industries such as pharmaceutical, nutraceutical, cosmetic, and agriculture.

Cutting reduces variation in biomass production of forage crops and allows low-performers to catch up: A case study of Trifolium pratense L. (red clover).

Re-growth of fodder plants after grazing and mowing drives the profitability of their cultivation and is therefore an important target trait for plant breeding and agricultural engineering. However, for some fodder plants little is known about their re-growth dynamics in response to grazing or mowing. We analysed the native response of plant architecture, leaf morphology and growth performance to experimental cutting in wild Trifolium pratense L. (red clover) plants. A total of 150 potted clover plants were established under controlled field conditions, and half of the plants were cut to 5 cm 3 months after sowing. Each plant was measured every week for 5 months. The cut and subsequently re-grown plants carried fewer main branches (-20%), as well as fewer (-13%) and smaller (-32%) leaves than the control plants. However, the cut plants produced an average of 17% more accumulated leaf area (cut + re-grown leaf area) than the control plants. This discrepancy was explained by variation in the growth strategy of the plants, where the cut plants invariably expressed a second growth phase, while almost half of the untreated plants did not. Our results suggest that cutting acted as an artificial trigger initiating a second growth phase in the cut plants and thereby contributed to yield increase. Exploiting this mechanism may set new goals for breeding and optimisation of the mowing regime.

Climate Clever Clovers: New Paradigm to Reduce the Environmental Footprint of Ruminants by Breeding Low Methanogenic Forages Utilizing Haplotype Variation.

Mitigating methane production by ruminants is a significant challenge to global livestock production. This research offers a new paradigm to reduce methane emissions from ruminants by breeding climate-clever clovers. We demonstrate wide genetic diversity for the trait methanogenic potential in Australia's key pasture legume, subterranean clover (Trifolium subterraneum L.). In a bi-parental population the broadsense heritability in methanogenic potential was moderate (H2 = 0.4) and allelic variation in a region of Chr 8 accounted for 7.8% of phenotypic variation. In a genome-wide association study we identified four loci controlling methanogenic potential assessed by an in vitro fermentation system. Significantly, the discovery of a single nucleotide polymorphism (SNP) on Chr 5 in a defined haplotype block with an upstream putative candidate gene from a plant peroxidase-like superfamily (TSub_g18548) and a downstream lectin receptor protein kinase (TSub_g18549) provides valuable candidates for an assay for this complex trait. In this way haplotype variation can be tracked to breed pastures with reduced methanogenic potential. Of the quantitative trait loci candidates, the DNA-damage-repair/toleration DRT100-like protein (TSub_g26967), linked to avoid the severity of DNA damage induced by secondary metabolites, is considered central to enteric methane production, as are disease resistance (TSub_g26971, TSub_g26972, and TSub_g18549) and ribonuclease proteins (TSub_g26974, TSub_g26975). These proteins are good pointers to elucidate the genetic basis of in vitro microbial fermentability and enteric methanogenic potential in subterranean clover. The genes identified allow the design of a suite of markers for marker-assisted selection to reduce rumen methane emission in selected pasture legumes. We demonstrate the feasibility of a plant breeding approach without compromising animal productivity to mitigate enteric methane emissions, which is one of the most significant challenges to global livestock production.