White Clover Research Articles

Microbial diversity and cover plants in de-sealed urban soil as strategies for mitigating anthropogenic volatile organic compounds

Urbanization exacerbates soil degradation, compromising global soil health and biodiversity. To reduce this, strategies for soil de-sealing and bioremediation are necessary. In a mesocosm experiment using a de-sealed soil from an urban site as substrate, an inoculum of arbuscular mycorrhizal fungi (AMF) and two cover plants, Cynara cardunculus L. and Trifolium repens L., were utilized to assess their effects on volatile organic compound (VOC) emissions and soil microbial community dynamics. The soil status was investigated employing soil VOC and metabarcoding analyses. Our results showed that the soil VOC emission was mainly composed by anthropogenic derived VOCs, especially arene and furan classes. These two classes were shown to be less concentrated in C. cardunculus soils, with and without AM fungal inoculation, suggesting a positive impact of these conditions on soil health restoration. Additionally, AM fungal inoculation of C. cardunculus resulted in increased bacterial alpha diversity, with enhanced Proteobacteria/Acidobacteria, Cyanobacteria/Chloroflexi, and Fungi/Bacteria ratios, suggesting an improvement in soil quality conditions. In our experimental conditions, order Chloroflexales and specific bacterial genera, including Ralstonia, Delftia, Ramlibacter, were identified as contributors to VOC degradation, highlighting their adaptability in contaminated environments. Overall, this study provided evidence on the importance of integrating AM fungal inoculation and specific flowerbed/ornamental plants in urban soil management after de-sealing processes.

Production performance and milk composition of late lactation dairy goats fed diets based on silages of four different forage species

The objective of the current trial was to evaluate the effect of feeding four different forage species on milk yield and composition, including protein and fatty acid profiles, in dairy goats. Two grasses (Timothy; mown at early heading, and Italian ryegrass; mown at 25 cm height) and two legumes (Alfalfa and White clover; both mown at 10% bloom) were harvested and conserved as silage. Twelve dairy goats of three different breeds (4 Alpine, 4 Toggenburg, and 4 Saanen) in late lactation were used in a replicated 4 × 4 Latin square design. Goats were offered ad libitum access to the tested forages supplemented with 180 g/d of concentrates based on rolled barley and heat-treated soybean meal. DM intake was lower with timothy, intermediate with ryegrass and white clover, and greater with alfalfa. Milk yield was lower with timothy as compared with the other three silages. Milk fat yield was similar among treatments. Milk CP yield was lower with timothy as compared with the other three silages. Milk N efficiency (N secreted/N intake) was greater with timothy, intermediate with ryegrass, and lower with the two legume silages. The proportion of true protein as a percentage of CP was lower in milk from goats fed legume as compared with grass silages. Proportions of casein and whey protein expressed as percentages of true protein were greater with timothy, intermediate with ryegrass and white clover, and lower with alfalfa. Among grass silages, intake and milk secretion of cis-9, cis-12 cis-15 18:3 was greater with ryegrass than with timothy. As a result, the transfer efficiency from dietary intake to secretion in milk was not different between these two treatments. Fewer differences were observed regarding legume forages, as cis-9, cis-12, cis-15 18:3 intake and milk secretion were similar with alfalfa and white clover. However, the transfer of cis-9, cis-12, cis-15 18:3 from diet to milk was highest when feeding alfalfa. In conclusion, forage species fed to dairy goats influence milk composition in terms of fatty acids and protein fractions, which can potentially impact the nutritive value and technological properties of milk.

Converting perennial ryegrass into lipid using the oleaginous yeast Metschnikowia pulcherrima

Grass, a low-cost lignocellulosic feedstock with relatively low lignin content, serves as a potential carbon source for microbial processes due to its polymeric sugar content. However, converting carbohydrates into monomeric sugars presents challenges due to complex lignocellulosic matrix. In this study, a mixture of perennial ryegrass and white clover (RG) was pretreated with alkaline before being enzymatically hydrolysed for use as a fermentable sugar source for the oleaginous yeast Metschnikowia pulcherrima. The dilute alkaline pretreatment approach resulted in a 3 times improvement in the conversion of RG, yielding a fermentable sugar concentration of 56.5 g/L. The yeast exhibited a growth yield (Ym/m) of 0.47, producing 23.7 g/L of dry cell weight at 20°C over 140 hours, with a lipid content of 37 % with a similar composition to high oleic palm oil. These findings suggest that RG can be utilised for formulating an oleaginous yeast medium containing the necessary nutrients.

Forage lucerne for grazing dairy cows: effects on milk yield, milk urea and fatty acid composition

Context The value of milk components is increasingly recognised for human health benefits (e.g. omega-3 fatty acids, FA), or indicators of nutrient-use efficiency for both animal and environmental benefits (e.g. milk urea, MU). Aims The study explored whether inclusion of lucerne (Medicago sativa L.) in a perennial ryegrass and white clover (Lolium perenne L. and Trifolium repens L, PRW)-based diet affects milk production, MU concentration, and milk FA composition of dairy cows during mid-lactation. Methods Thirty-two cows, balanced for milk production (26.1 ± 3.03 kg/cow), MU (16.6 ± 2.84 mg/dL), and days in milk (94 ± 7 days), were evenly allocated into eight groups of four. Groups were then randomly assigned one of two dietary treatments, namely, PRW only (control), and PRW plus lucerne (lucerne). During an 8-day adaptation, control cows were fed a fresh allocation after each milking at 08:30 hours and 16:00 hours to provide 25 kg/cow.day DM of fresh PRW herbage above a target post-grazing height of 4.5 cm height. Cows on lucerne were allocated 10 kg DM of fresh lucerne at 08:30 hours, and 15 kg DM of fresh PRW at 16:00 hours. Apparent nutrient intakes and milk composition were determined on Days 9 and 10 of the study. Key results Diet treatment did not significantly alter DM or metabolisable energy intake, milk production, or milk fat and protein percentage. However, compared with control cows, nitrogen and linoleic acid (LA) intake increased, and soluble carbohydrate, neutral detergent fibre, and alpha linoleic acid (ALA) intake decreased for cows fed lucerne. Milk urea increased by 43% for lucerne compared with control cows (22.4 vs 15.7 ± 1.43 mg/dL, P < 0.001). Cows grazing lucerne produced milk with a higher concentration of LA and ALA than did the control cows. Increases in milk LA from grazing lucerne were congruent with improvement in intake of the FA from the diet, whereas increases in ALA occurred despite the corresponding lower dietary intake. Conclusion Supplementing a pasture diet with lucerne increased MU and FA. Implications Lucerne has the potential to enhance dietary protein supply during periods of deficiency and increase the supply of functional FA in the milk of grazing dairy cattle.

Vegetation Restoration Patterns Influence the Supply and Interrelations of Grassland Ecosystem Services in Karst Desertification Control

An appropriate vegetation restoration pattern is crucial for maintaining and enhancing ecosystem functions and services in karst rocky desertification control areas. However, it is still unclear whether different vegetation restoration patterns will aggravate the trade-off of grassland ecosystem services in this area. This study focuses on grassland ecosystems in the karst desertification control area, comparing artificial restoration measures (Dactylis glomerata single-species sowing grassland, DG; Lolium perenne single-species sowing grassland, LP; Lolium perenne + Trifolium repens mixed-species sowing grassland, LT) with natural restoration measures (NG). Seven ecosystem services (forage yield, soil retention, soil water conservation, carbon fixation and release, soil carbon storage, soil nutrient retention, and biodiversity conservation) as well as total ecosystem services were quantified using field monitoring data. The relationships between these services were evaluated through Spearman correlation analysis. The results showed that different vegetation restoration patterns significantly influenced the provisioning, regulating, and supporting services of the grassland ecosystem (p < 0.001). Three types of relationships were observed (trade-off, synergy, and neutral), but the trade-off relationship was not significant (p > 0.05). The total ecosystem service of LT (0.79) was significantly higher than that of NG (0.21), DG (0.36), and LP (0.41), with a significant synergy observed between soil nutrient conservation, forage yield, and carbon sequestration and oxygen release (p < 0.05). Therefore, LT is considered the best vegetation restoration practice for the karst rocky desertification control area compared with other patterns. This study provides theoretical guidance for vegetation restoration in degraded karst ecosystems.

Transitioning from traditional to robotic mowing affects turfgrass quality and broadleaf weeds on golf course fairways

AbstractOn European golf courses, small lightweight robotic mowers have recently been introduced for fairway and rough mowing. In this study, turfgrass quality and the coverage of broadleaf weeds in three cool‐season grasses were compared in response to robotic and traditional fairway mowing. Experiments with pure swards of red fescue (Festuca rubra L.), colonial bentgrass (Agrostis capillaris L.), and Kentucky bluegrass (Poa pratensis L.) were carried out at NIBIO Landvik, Norway, to evaluate differences between lightweight robotic mowing and reel mowing. In a mixture of the three species turfgrass quality and the coverage of broadleaf weeds were compared in response to robotic and reel mowing at yearly fertilizer levels from 0 to 120 kg N ha−1. The results showed that both robotic and reel mowing were found to provide high turfgrass quality, while lower coverage of broadleaf weeds (predominantly white clover [Trifolium repens L.]) was found with robotic mowing independent of grass species. In the mixed stand, higher turfgrass quality was found with robotic mowing regardless of N rate, but N rates above 60 kg ha−1 year−1 were necessary to keep the coverage of white clover in fall on an acceptable low level. Our results suggest that robotic mowing can decrease the spread of white clover at a fairway mowing height of 15 mm, but more research is needed to clarify at which mowing heights, mowing frequencies, and fertilizer levels we can get the best competitiveness against broadleaf weeds on fairways with robotic mowing.

Evaluation of forage resources under poorly drained soils for dairy systems

Alfalfa is crucial for dairy farms, but its potential production and persistence can be hindered by waterlogging, poorly drained soils, and high-water tables. The objectives of this study were (a) to evaluate herbage mas and quality of different forage species on poorly drained soils, and (b) to evaluate root biomass accumulation and their impacts on soil physical properties. The study was conducted in Santa Fe, Argentina, on an Aquic Argiudoll. Four treatments were established in March 2017: Alfalfa (control), Fescue, Annual (Ryegrass and Sorghum rotation regime), and Mixture (a mixture of Brome, Chicory, Red clover, and White clover). Aboveground herbage mass and nutritive quality were analyzed frequently, while roots and soil samples were collected after 2 years for further analysis. Root biomass was significantly higher (p < 0.05) in Annual and Mixture pastures compared to Alfalfa and Fescue. Lower root biomass in Alfalfa was attributed to temporary waterlogging and low plant density. Fescue exhibited reduced root biomass due to higher bulk density and lower soil porosity. Soil bulk density was lowest in Mixture, and no significant differences in soil penetration resistance were found among treatments (p > 0.05). There are alternatives to alfalfa with high production and quality that ensure a good economic return to farmers. The choice of forages for its root biomass accumulation has effects on the physics of the soil that ultimately modify the water dynamics. These findings have implications for sustainable forage management strategies, particularly in areas prone to waterlogging and poorly drained soils.

Cover crops lower the dispersal of grapevine foliar pathogens from the ground and contribute to early-season disease management.

Currently, fungicides are widely used to control grapevine foliar diseases. This study explored the possibility of decreasing the use of fungicides to control these diseases using cover crops in the inter-row of vineyards. In small-scale experiments, we found that cover crops (namely horseradish Armoracia rusticana) were able to (i) reduce the numbers of airborne conidia of Botrytis cinerea (originating from an inoculum source above the soil) escaping the cover canopy by >85% with respect to the base soil and (ii) reduce the number of raindrops impacting the soil by 46%-74%, depending on the cover crop height and rain-originated splash droplets that escaped from the ground by 75%-95%, which reduced splash-borne inoculum. In two organic vineyards, for 2 years, fall- (mixture of Lolium perenne, Onobrychis viciifolia, and Trifolium repens) or spring-sown (a mixture of Vicia sativa and Sinapis sp.) cover crops could significantly delay (by 14-30 days) and reduce (till >90%) the development of downy and powdery mildew epidemics. This effect was more evident in plots untreated with fungicides than in treated plots. Cover crops also delayed the onset of epidemics depending on the type of cover crop and disease. Cover crops did not negatively affect grape yield and quality. Overall, the results showed that the introduction of cover crops in vineyard management can significantly contribute to disease control by lowering the load from ground to grapevine canopies of pathogen inocula, delaying disease onset, and reducing diseases severity during the season.

Comparison of Productivity and Quality of Three Perennial Ryegrass Cultivars and Their Mixture in Response to Nitrogen Fertilization and Grass-Legume Mixtures.

We conducted a four-year cutting experiment on herbage yield, with three years focused on testing the effect of perennial ryegrass (PR) cultivars 'Elena DS', 'Raminta', and 'Verseka', along with a cultivar mixture and compositions with white clover (WC) and red clover (RC) diversity, on crude protein (CP), modified acid detergent fibre (MADF), neutral detergent fibre (NDF), water-soluble carbohydrates (WSC), and dry matter digestibility (DMD) content. PR cultivars and cultivar mixtures were sown alone (N150), and the PR 'Elena DS' and PR cultivar mixtures were also sown with each WC, or WC and RC (N0). The average four-year herbage productivity was the lowest in PR 'Elena DS' the and cultivar mixture/WC, followed by all of the pure PR swards, and the highest in PR 'Elena DS' and the cultivar mixture/WC+RC; however, the PR 'Elena DS'/WC+RC mixture had the highest legume proportion and CP content. There was less NDF but also WSC in swards with legumes, but higher CP content than in pure PR swards; however, the highest CP content was in mixtures with RC. Among the grasses, PR 'Verseka' had lower NDF contents and a higher WSC than PR 'Elena DS', 'Raminta', and the cultivar mixture. Overall, this study revealed significant differences in the productivity of PR cultivars with a potential yield difference of up to 1.7 t ha-1.

Flue-cured tobacco intercropping with insectary floral plants improves rhizosphere soil microbial communities and chemical properties of flue-cured tobacco

BackgroundContinuous cropping of the same crop leads to land degradation. This is also called the continuous-cropping obstacle. Currently, intercropping tobacco with other crops can serve as an effective strategy to alleviate continuous cropping obstacles.ResultsIn this study, tobacco K326 and insectary floral plants were used as materials, and seven treatments of tobacco monoculture (CK), tobacco intercropped with Tagetes erecta, Vicia villosa, Fagopyrum esculentum, Lobularia maritima, Trifolium repens, and Argyranthemum frutescens respectively, were set up to study their effects on rhizosphere soil chemical properties and composition and structure of rhizosphere soil microbial community of tobacco. The 16 S rRNA gene and ITS amplicons were sequenced using Illumina high-throughput sequencing. tobacco/insectary floral plants intercropping can influence rhizosphere soil chemical properties, which also change rhizosphere microbial communities. The CK and treatment groups tobacco rhizosphere soil microorganisms had significantly different genera, such as tobacco intercropping with T. repens and A. frutescens significantly increased the number of Fusarium and intercropping T. erecta, V. villosa, L. maritima, T. repens, and A. frutescens significantly increased the number of Sphingomonas and unknown Gemmatimonadaceae. Additionally, intercropping T. erecta, V. villosa and L. maritima changed the rhizosphere fungal and bacteria community and composition of tobacco and the positive correlation between tobacco rhizosphere the genera of fungi and bacterial were greater than CK. The pathway of the carbohydrate metabolism, amino acid metabolism, and energy metabolism in rhizosphere bacteria were significantly decreased after continuous cropping. Fungal symbiotic trophic and saprophytic trophic were significantly increased after intercropping V. villosa, L. maritima and plant pathogen and animal pathogen were increased after intercropping T. repens and A. frutescens. Additionally, bacterial and fungal communities significantly correlated with soil chemical properties, respectively.ConclusionThis study reveals that intercropping tobacco with insectary floral plants, particularly T. erecta, V. villosa, L. maritima and A. frutescens significantly affects soil chemical properties and alters rhizosphere microbial communities, increasing the abundance of certain microbial genera. Additionally, intercropping enhances pathways related to carbohydrate, amino acid, and energy metabolism in rhizosphere bacteria. These findings suggest that intercropping could provide a promising strategy to overcome challenges associated with continuous tobacco cropping by regulating the rhizosphere environment.

Benefit of weeds for crop-plant mycobiota in agroecosystems: Integrating ecological demonstration and management applicability

Agricultural intensification reduces not only biodiversity in agroecosystems but also key ecosystem functions such as soil fertility. By reintroducing biological diversity in fields, weeds may enhance soil biological fertility through their influence on crop microbiota. However, letting weeds grow in crop fields will depend on weed competitiveness, farmers’ perception and acceptance, and on crop management, which influences the occurrence and the abundance of weeds in the field. This study assessed the use of eight weed species to modify wheat plant root endospheric mycobiota, and the applicability of using these plants for mycobiota enrichment in the field. By combining controlled lab experiments and field studies, we demonstrated that weeds act either as a refuge for a high diversity of fungi or as a vector for transferring fungi to the crop, particularly symbionts. Weeds differed in their competitive effect on wheat growth and only three species significantly reduced wheat growth. Interviews with farmers’ revealed that weed species were better known and more appreciated in crop fields by organic farmers than by conventional farmers. Floristic surveys confirmed that both weed occurrence and cover were higher in organic fields than in conventional fields. A multicriteria analysis showed that Trifolium repens and V. persica had the highest potential for promoting wheat plant mycobiota. Among the weed species tested, these two are worth considering as auxiliaries to improve soil biological fertility in crop fields. Their use with the goal of selecting appropriate crop mycobiota should be relatively easier in organic farms where weeds are better accepted, whereas their use in conventional farms would require raising farmers’ awareness of the benefits of weeds for soil fertility.

Carry‐Over Effect of Leguminous Winter Cover Crops and Living Mulches on Winter Wheat as a Second Main Crop Following White Cabbage

ABSTRACTBackgroundThe direct effect of winter cover crops (WCCs) or living mulches (LMs) on a first vegetable crop has already been investigated. However, little is known about the effect on growth and yield of a second cash crop in the rotation.AimsThe aim of the study was to assess the carry‐over effect of legumes grown as WCC or LM on winter wheat as a second crop after cabbage, measured in yield and nitrogen release.MethodsTwo field trials were carried out in Germany between 2019 and 2022. In the WCC trial, rye, rye with vetch, vetch, pea, and faba bean were used as WCC and compared to bare soil. The WCC biomass was incorporated before cabbage planting in late spring. For the LM trial, perennial ryegrass or white clover was used as LM during cabbage cultivation and compared to bare soil. The LM biomass was incorporated with the cabbage residues and compared to an early incorporation of LM biomass before cabbage planting. In both trials, winter wheat was sown in the fall as the second following main crop in the rotation.ResultsLeguminous WCC species had significant higher wheat yield compared to non‐legumes but not compared to the control without WCC. Late incorporation of LM biomass resulted in increased wheat yield at 10.1–10.4 Mg ha−1 compared to an early incorporation before cabbage planting at 9.35 Mg ha−1. Net N releases show that for WCC, the main effect of legume nitrogen fixation is achieved in the first crop cabbage immediately after incorporation of WCC biomass. In the case of leguminous LM, the effects of legume nitrogen fixation are of much higher relevance in the second main crop, winter wheat, due to LM biomass incorporation after cabbage cultivation.ConclusionTherefore, we suggest to consider not only the direct but also the carry‐over effects of leguminous cover cropping in vegetable crop rotations.

Multi-year performance of white clover oversown into eastern North Island hill country

Animal performance on summer-dry North Island hill country pastures is limited by soil fertility and the challenge of establishing and retaining a strong legume base in swards on steeper slopes. However, this can be overcome by 1. selecting legume species adapted to the various slope, aspect and soil type combinations; and 2. following well-recognised establishment and management techniques developed in the 1980s. We broadcast white clover in two large southerly aspect paddocks on Tangihanga Station, Gisborne, in the autumn of 2019. Establishment methods involved resident pasture control by hard grazing and selective herbicide to supress dominant low-fertility grasses, broadcasting at high sowing rates and trampling of seed with sheep. We followed white clover persistence and animal performance over the subsequent 5 seasons of rotational cattle grazing with heifers and steers, in comparison with adjacent unsown paddocks. The cost of establishment was c. $220/ha. White clover abundance remained high throughout the 5 years, between 25-40% of cover, compared with 7-17% in unsown paddocks. This increase in clover content of the pastures translated into both increased stocking rates and per head growth rates, with overall annual LWG increasing by 67-169% depending on season. The investment was paid back within the first year.

Allelopathic Effects of Soil Extracts from Rhus typhina Plantations on Common Turfgrass Species in Northern China

The allelopathic plant Rhus typhina (Rt) has a shallowly distributed root system with a high density of secretory canals, which may allow it to exhibit indirect allelopathic effects through the soil on an understory turf species in a plantation. However, how these effects occur is still not well understood. For this study, the soil from the root zone of Rt was extracted via distilled water, and extracts at different concentrations (25, 50, and 100 g L−1) were used to treat six commonly planted turfgrass species, including Medicago sativa (Ms), Lolium perenne (Lp), Trifolium repens (Tr), Medicago falcata (Mf), Festuca arundinacea (Fa) and Coronilla varia (Cv), during a continuous germination–seedling culture experiment via the sand culture method. The germination, physiological, and growth indicators of the turfgrass seedlings were analyzed. The allelopathic effects of the soil extract at different concentrations on the six receivers were evaluated to provide a scientific basis for managing plantations with multilayer structures. The results indicated that, in general, the extracts of the soil from the root zone of Rt inhibited the germination and seedling growth performance characteristics of the mentioned turfgrasses; the inhibitory effects on Ms, Lp, and Mf increased with increasing concentrations of the Rt soil extracts, whereas those on Fa tended to decrease. In addition, the inhibitory effect on Tr obviously weakened at 50 g·L−1 relative to that at 25 g·L−1, whereas it became more obvious at 100 g·L−1; however, it exhibited the opposite trend for Cv. Generally, Mf and Cv were more sensitive to Rt allelochemicals at relatively low concentrations, and these species should be avoided when planting in Rt plantations at low densities. In contrast, Lp and Tr were more sensitive than those at relatively high concentrations and should be avoided when planting in Rt plantations at high densities.

Animal performance over 16 years after implementing a lucerne grazing system on Bog Roy Station - a case study

In 2023, the animal performance data for Bog Roy station show 151 t weaned lamb is being produced from 4272 ewes plus 9.0 t from hogget lambs. The ability to mate merino hoggets has resulted from increased feed supply that means mixed age ewes are now consistently averaging 65.6±1.17 kg/hd at mating (2019-2023). This has enabled an emphasis on two-tooth weight at mating, which has also increased 0.74±0.14 kg/hd/yr (R2 = 0.64) from 52 kg/hd in 2012 to 61 kg/hd in 2023. Consequently, scanning is consistently ~167±1.59% for the mixed age ewes (2012-2023) and increased from 113% (2008) to 154% (2023) in the two-tooths. Lamb wastage for the mixed age ewes has decreased 0.70±0.08%/yr (R2 = 0.88) to 15% in 2023 and, although more variable (R2 = 0.13), the wastage in two-tooths has also reduced from 32% (2014) to 21% (2023). Lamb wastage is negatively related to two-tooth weight at set-stocking, so feeding young stock is a priority. Since 2016, pre-weaning merino lamb growth rates have averaged 286±4.39 g/hd/d with weaning now at 79.3±2.56 days. This consistency coincided with the addition of 210 ha of feed under pivot irrigation that was initially sown in red and white clover and is now in lucerne/grass mixes. The additional feed has meant wool production has remained constant throughout the 15 years of pasture development. Cow numbers have been used to buffer the changes in pasture supply as the dryland and pivot development occurred. These have now increased to their highest level since the development began. The major change in farm income has resulted from the earlier sale of more lambs at a higher average price because they are heavier due to the extra feed. This unique long-term dataset of on-farm performance provides a commercial example of transformational change that has resulted from changes in the farm system, driven by direct feeding of dryland lucerne and irrigation development focused on growing young stock in this 420 mm rainfall environment.

Subterranean clover growth responded to grass suppression, phosphorus and molybdenum fertilisers in a summer dry hill environment

Pastures on the north-facing slopes of the Port Hills, Canterbury, are summer-dry, grass dominant, and have low soil phosphorous and sulphur fertility. The aim of this experiment was to improve the establishment of oversown subterranean (sub) clover by the addition of fertilizer and grass-supressing herbicide. Treatments were a factorial combination of phosphorous (0 or 60 kg P/ha, -P or +P), sulphur (0 or 50 kg S/ha, -S or +S), and molybdenum (0 or 0.06 kg Mo/ha, -Mo or +Mo), with or without autumn herbicide (plus or minus, +H or -H). Fertilisers were applied in 2021, with P and S reapplied in 2023, and herbicide applied in 2022 and 2023. Pasture yields were measured annually from 2021 to 2023. Measurements in 2021 found no fertiliser effect on total pasture yield of 3650±83 kg DM/ha that included 770±43 kg of sub clover. In 2022, P addition increased total pasture yield from 2900 to 3270 kg DM/ha. Herbicide application doubled the sub clover yield from 310 to 645 kg DM/ha and reduced grass from 1650 to 1410 kg DM/ha. In 2023, the herbicide application did not affect the total accumulated pasture yield (10180±160 kg DM/ha) but increased sub clover content from 10 to 25% and reduced the grasses from 63 to 47%, with about 4% white clover. Where herbicide was applied without fertiliser (+H), total clover yield increased from 1460 to 2930 kg DM/ha. The application of P and Mo, (i.e., +H+P+Mo treatment) increased it further to 4010 kg DM/ha. There was no yield response to +S or +Mo unless added with P. Applying herbicide or phosphorous increased total metabolisable energy from 38.5 to 42.6 GJ ME/ha and crude protein from 500 to 595 kg/ha in pastures sampled in November 2023. The treatment combination providing the highest feed quality values was +H+P+Mo. These results suggest that to optimise sub clover content of pastures on the Port Hills competing grasses must be controlled initially, followed by P fertiliser if soil tests indicate it is required along with molybdenum.

Condensed tannin expression in white clover leaves for enhanced animal health benefits

Condensed tannin expression in white clover leaves for enhanced animal health benefits

Can additives or controlled release coating improve the nitrogen use efficiency of urea fertiliser

A plot trial was undertaken to determine whether tactical use of nitrogen (N) fertiliser applied with or without coating or biostimulant improved herbage yield and N use efficiency. A randomised complete block design was used to compare no fertiliser (CON), frequent low rates of urea (FL), infrequent moderate rates of urea (IM), IM with controlled release (IM+CR), IM with Progibb (IM+PG), IM with Agrisea (IM+AS), or IM with N-Boost (IM+NB) on irrigated, grazed perennial ryegrass and white clover dairy pastures in Canterbury. The total annual N applied in all fertilised treatments was 190 kg N/ha. The use of fertiliser increased annual herbage yield (16.9±0.44 vs 14.5 t DM/ha/y; P&lt;0.05). Combining urea with a coating or biostimulant altered the distribution of pasture growth, but did not affect net annual production or herbage quality. Due to the lack of response and greater application costs with liquid versus granule products, these results highlight the need to consider expected responses to different fertiliser regimes when adopting practices to achieve economic benefits and N efficiency.

Survival of white clover rhizobium isolate S11N9 in different delivery systems: assessment of potential for commercialisation

Survival of white clover rhizobium isolate S11N9 in different delivery systems: assessment of potential for commercialisation

Animal behaviour and dietary preference of dairy cows grazing binary and diverse pastures under the leaf regrowth stage defoliation criterion

In New Zealand, intensively managed pasture-based dairy systems rely on binary pastures mostly comprised of Lolium perenne L. and Trifolium repens L.. More frequent and extreme climatic events have been negatively affecting the persistency and production of these pastures, which now present increased seasonality, with marked peaks and troughs of production throughout the year. Diversification of plant species offers a solution to deal with increased seasonality. However, little is known about animal behaviour and dietary preferences of dairy cows grazing diverse pastures. The present study aimed to assess the grazing preferences of dairy cows when unrestrictedly offered binary (L. perenne and T. repens; Bi) and diverse pastures (L. perenne, Bromus valdivianus Phil., Dactylis glomerata L. and T. repens; Mix) subjected to three different leaf regrowth stage (LS) defoliation criteria. Secondarily, the study aimed to determine the main plant-related drivers for any potential animal preference. The treatments were MixLp (defoliated at L. perenne LS), BiLp (defoliated every time MixLp was defoliated), MixBv (defoliated at B. valdivianus LS) and BiBv (defoliated every time MixBv was defoliated), MixDg (defoliated at D. glomerata LS) and BiDg (defoliated every time MixDg was defoliated). Dairy cattle were evaluated over five agricultural seasons. The response variables were grazing time and location, bite rate, animal behavioural activity, pre-grazing herbage mass, undisturbed sward height, lamina:stem ratio, crude protein, metabolisable energy, organic matter digestibility, non-structural carbohydrates, neutral detergent fibre and lignin. Where significant differences were found, binary pastures presented lower sward height and higher non-structural carbohydrate content in comparison to the diverse pastures under the same LS defoliation criteria. However, no significant differences were found in the percentage of time that cows spent grazing both pastures. Season was the greatest contributor to the proportion variation found in all response variables, with values ranging from 47.55 % up to 88.77 %. In winter and spring, cows modulated their grazing behaviour (proportional time spent grazing, ruminating, or idling), investing more time actively grazing pastures under L. perenne LS interval of defoliation (2.5–3.0 LS), the criterion which resulted in shorter grazing rotations. This study allowed us to understand the suitability of diverse pastures from an animal perspective, and highlighted that independent of the pasture type, the positive productive and nutritional effects of defoliation management based on the LS may also extend themselves to positive outcomes in animal preference, interpreted as the percentage of time dairy cows spend grazing rather than ruminating or idling across and within seasons.