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Reduced reliance on inputs such as fertilizer is fundamental to sustainable grazing systems. This two‐year study compared four sward types, including multispecies swards (MSS), for herbage dry matter (DM) production, species contribution to DM, and herbage nutritive value under grazing. The systems were: (1) Lolium perenne L. monoculture (PRG; 170 kg N ha−1 year−1); (2) permanent pasture (PP; 135 kg N ha−1 year−1), (3) six species sward consisting of two grasses, two legumes and two herbs (6S; 70 kg N ha−1 year−1), (4) twelve species sward consisting of three grasses, four legumes and five herbs (12S; 70 kg N ha−1 year−1). Herbage samples were collected for DM yield, botanical composition, and nutritive value. Mean annual DM production for PRG, PP, 6S, and 12S was 11,374, 8526, 13,783, and 13,338 kg DM ha−1 respectively. Herb proportions decreased in 6S and 12S from 2020 to 2021 while grass proportions increased. Mean crude protein levels were similar across all systems (p > 0.05), with higher ash content in 6S and 12S compared to PRG (p < 0.001). Organic matter digestibility was lowest in PP compared to PRG (p < 0.001) while neutral detergent fibre content of PP and PRG were greater than 6S and 12S (p < 0.001). Water soluble carbohydrate content was highest in PRG (p < 0.0001). Over 2 years, MSS delivered increased herbage DM yield and nutritive quality relative to PRG and PP swards, from reduced N inputs. However, maintenance of the herb component of MSS is a challenge. [ABSTRACT FROM AUTHOR]

Agrivoltaic systems combine solar energy and agriculture, promoting dual land use. Although grazing sheep in these systems is common, research on intentionally designed pastures to increase production is lacking. This study seeks to compare the herbage growth and lamb production in simple, diverse, and legume pastures in an agrivoltaic system over 2 years in Oregon. Annual herbage production in diverse pastures (4583 kg DM ha−1) was comparable to simple pastures (4457 kg DM ha−1), but higher than legume pastures (p <.05; 4023 kg DM ha−1) for the 2020/2021 growing season. In the 2021/2022 growing season, diverse pastures had a higher yield (4660 kg DM ha−1, p <.05) than simple pastures (4052 kg DM ha−1), which were similar to legume pastures (3955 kg DM ha−1). Liveweight gain (LWG; g head−1 d−1) tended (p =.06) to be higher from lambs in diverse and legume pastures compared to simple pastures in spring 2021. Liveweight production (LWP; kg ha−1 d−1) of legume pasture were greater (P < 0.05) than other pasture types, while simple pastures had the lowest LWP during this period. In summer 2021, LWG tended to be greater in lambs grazing diverse versus simple pastures. No difference was detected (all p >.05) in LWG or LWP at any grazing period in 2022. Overall, efficiency of pasture production was greatly reduced by lower light availability in all pasture types. Diversification of pastures using forbs in agrivoltaics was a good strategy for greater herbage production, while the legume pastures had poor persistence. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the influence of botanical composition calibration on the accuracy of undisturbed sward height and comparative yield method (CYM) techniques for herbage mass estimation in tropical heterogeneous pastures. Two studies were conducted using two grazing systems based on heterogeneous pastures. Herbage mass was estimated using CYM and undisturbed sward height techniques within quadrats (SHQ) or at a set of standard points in the paddocks (SHP). SHQ had a higher adjusted R2 when calibrated with the Urochloa brizantha cv. Marandú (U. brizantha) proportion compared to the simple SHQ model (0.75 vs 0.68), while RSE was lower (0.18 vs 0.21). The R2 increased (0.63 to 0.68), while both residual means and RSE decreased (−2.30 to –0.05 and 0.22 to 0.20, respectively) when SHP was calibrated with U. brizantha. It also resulted in a reduction of mean squared prediction error (MSPE) to CYM, SHQ, and SHP, respectively. The CYM allows for higher accuracy of herbage mass estimation in tropical heterogeneous pastures than undisturbed sward height, irrespective of botanical calibration. However, the botanical composition calibration had positive effects on the models from undisturbed sward height, and the calibration with U. brizantha increased the accuracy of herbage mass prediction. [ABSTRACT FROM AUTHOR]

Many cool-season pastures in the southeastern U.S. are dominated by a competitive cool-season grass, tall fescue (Schedonorus arundinaceus), and lack substantial plant diversity. Planting native warm-season grasses (NWSGs) and wildflowers (WFs) into these pastures could provide summer forage for cattle and more floral resources for pollinators. This paper summarizes field experiments designed to evaluate different spatiotemporal planting arrangements of NWSGs and WFs to improve their establishment success. The study was conducted from April 2021 to October 2023 in central Virginia (USA). Planting treatments included NWSG and WF mixtures planted: (1) together in the same space, (2) spatially separated in space (i.e., side by side), or (3) temporally separated where NWSGs and WFs were planted in difference sequences. Results showed few differences in forage mass, floral production, and botanical composition as well as stand density in 2021 and 2022. In 2023, NWSG abundance was greater where grasses were planted first or mixed with WFs. Similarly, the WF component was favored when they were planted before NWSGs. Overall, planting NWSG and WF mixes separately, either spatially or temporally, favors successful establishment and could offer more flexibility for using selective herbicides to suppress the heavy weed pressure that often accompanies these plantings. [ABSTRACT FROM AUTHOR]

Pests in pastures have compromised the production of biomass for feeding livestock herds. Many strategies have been applied to sustainably solve this problem. One viable and innovative technique is the delivery of entomopathogenic fungi through endophytes. Therefore, this study aimed to (i) evaluate the endophytic capacity of two entomopathogenic fungi, Fusarium multiceps UFMGCB 11443 and Metarhizium anisopliae UFMGCB 11444, in Urochloa brizantha [(Hochst. ex A. Rich.) Stapf] (Poaceae) cultivar 'Marundu') via foliar inoculation or seed treatment, and (ii) measure their efficiency in controlling Mahanarva spectabilis Distant, 1909 (Hemiptera: Cercopidae) in U. brizantha. In the greenhouse, the fungi colonized the tissues of U. brizantha plants when inoculated via foliar spraying or seed treatment. The fungi F. multiceps and M. anisopliae caused 88% and 97.1% epizootic effects via seed inoculation, respectively, and 100% epizootic effects via foliar inoculation. In the field, the lowest fungal dose of 0.5 kg/ha had the same effect as a fourfold greater dose, with a >86% decrease in insect pest infestation observed. In summary, the fungi F. multiceps and M. anisopliae have endophytic effects and can effectively control M. spectabilis in U. brizantha pastures. [ABSTRACT FROM AUTHOR]

Rising platemeters are commonly used in Ireland and New Zealand for managing intensive pastures. To assess the applicability of a commercial rising platemeter operating with a microsonic sensor to estimate herbage mass with its own equation, the objectives were (i) to validate the original equation; (ii) to identify possible factors hampering its accuracy and precision; and (iii) to develop a new equation for heterogeneous swards. A comprehensive dataset (n = 1511) was compiled on the pastures of dairy farms. Compressed sward heights were measured by the rising platemeter. Herbage mass was harvested to determine reference herbage availability. The adequacy of estimating herbage mass was assessed using root mean squared error (RMSE) and mean bias. As the adequacy of the original equation was low, a new equation was developed using multiple regression models. The mean bias and the RMSE for the new equation were overall low with 201 kg dry matter/ha and 34.6%, but it tended to overestimate herbage availability at herbage mass < 500 kg dry matter/ha and underestimate it at >2500 kg dry matter/ha. Still, the newly developed equation for the microsonic sensor-based rising platemeter allows for accurate and precise estimation of available herbage mass on pastures. [ABSTRACT FROM AUTHOR]

In tropical regions, grass silage can be produced from the pasture in the rainy season to feed animals during the dry season. We evaluated the chemical composition and fermentation characteristics of ensiled signal grass (Urochloa decumbens Stapf. Basilisk) fertilized with nitrogen (N) or intercropped with calopo (Calopogonium mucunoides Desv.) with and without microbial inoculant. We used a 4 × 2 factorial scheme in a randomized block design, with two blocks and two treatments per block, considering p > 0.05. We studied signal grass fertilized with 0 kg ha−1 of N (0 N), 50 kg ha−1 of N (50 N), or 100 kg ha−1 of N (100 N), or intercropped with calopo legume (LEG), with (I) or without (WI) inoculant, in two seasons. During the dry–water transition, lower concentrations of butyric acid were observed in 50 N and LEG silages (2.77 and 2.55 g kg−1 dry matter, DM) (inoculated) compared to control (7.77 g kg−1 DM). During the water–dry transition, higher concentrations of crude protein were observed in 100 N and LEG silages (71.90 and 54.6 g kg−1 DM) than in 0 N (46.3 g kg−1 DM). The signal grass–calopo intercropping is an alternative to nitrogen fertilization, as it provides forage with a higher protein content and silage with satisfactory fermentative characteristics. [ABSTRACT FROM AUTHOR]

The use of chemical inputs has led to the loss of microbial diversity involved in the N cycle, such as diazotrophic bacteria, which are inhibited by saturation of the receptors responsible for activating nitrogenase. Biological nitrogen fixation (BNF) in forage grasses can be used as an ecosystem service. The aim of this review was to analyze the contribution of forage grasses to BNF and their response to inoculation of non-symbiotic diazotrophs in order to find study opportunities. The analysis of the information was carried out using the prisma methodology of systematic reviews and meta-analyses. It should be noted that the main forage species that contribute to BNF are Brachiaria sp. and Pennisetum sp. The inoculation of Azospirillum sp. has generated a growth-promoting effect in grasses, but the response of the inoculated forage depends mainly on the synergy between plant and bacteria, showing neutral, antagonistic, and positive effects. [ABSTRACT FROM AUTHOR]

The interaction between pasture and supplementation in dairy production systems constitutes a very important part of the efficiency of dairy. This study evaluated the effect of the herbage mass (HM) on the milk production and solid concentration. Twenty Holstein cows were distributed into two groups, 10 assigned 2200 kg DM ha-1 (low herbage mass, LHM) and 10 with 2800 kg DM ha-1 (medium herbage mass, MHM). Herbage mass was measured above 5 cm. The experiment lasted 8 wk. The variables evaluated were DM intake (DMI), milk production and composition (fat and protein concentration). Effects of treatments on variables were evaluated using a repeated measure analysis over time. The results showed nonsignificant differences in the pasture DMI between LHM and MHM for weeks 1, 2, 3 and 5 (P > 0.05). During week 4, pasture DMI was 3 kg greater for LHM than MHM (P < 0.05). The milk production did not differ between treatments per week, but the average was 2.4 kg greater for LHM compared to MHM (P < 0.05). In conclusion, changes in the pasture availability increased milk production at LHM, but not enough to cause changes in solids concentration. This clearly shows that, LHM can increase milk and solids production. [ABSTRACT FROM AUTHOR]

This study compared animal performance and enteric methane (CH4) emissions from dairy cows in a part-time grazing (PTG) system in northern Sweden. Twenty-four Nordic Red dairy cows were allocated to one of two treatments: DAY (10 h daytime pasture access) or NIGHT (12 h night-time pasture access). The cows in each treatment received the same ad libitum partial mixed ration (PMR) indoors and ad libitum herbage allowance. Methane was recorded using two linked GreenFeedTM emissions monitoring (GEM) units, on pasture and indoors. Day or night grazing showed no statistical differences in estimated grass or PMR intake, milk production or daily enteric CH4 emissions. There was a rapid decrease in diurnal CH4 emissions (28%) when the cows were moved from indoors to pasture in both grazing treatments. Using two GEM units (indoor, outdoor) in combination improved the diurnal assessment of enteric CH4 emissions during PTG conditions in the mixed feeding system. [ABSTRACT FROM AUTHOR]

One of the main constraints for sheep production in tropical and subtropical areas is the lack of knowledge of how to manage erect tropical grasses for lambs. The objective of this study was to assess the effect of pasture height and structure of an erect tropical grass, Aruana Guinea grass (Megathyrsus maximus cv. IZ-5) on the intake and performance of young weaned lambs. The experiment was repeated in two consecutive years. Thirty young weaned lambs were equally assigned, each year, to three pasture heights: (1) Tall 75 cm; (2) Medium 50 cm and (3) Short 25 cm. Herbage mass (HM), pasture height, plant morphological composition, pasture nutritional quality, lambs' average daily gain, gain per hectare and herbage intake were measured. The Short treatment had higher (p < 0.05) leaf:stem ratio (L:S; 2.6 ± 0.27) and average daily gain (ADG; 92 ± 10 g day−1) than the Tall treatment (0.9 ± 0.11 and 40 ± 13 g, respectively). The Medium treatment showed intermediate ADG (69 ± 11 g) and L:S ratio (1.4 ± 0.09). The height of the pasture affects the rate at which the number of stems increases relative to the number of leaves. There was a significant interaction between treatment and period (summer and early autumn) for herbage intake. Intake decreased markedly on the Tall treatment from the first to the second period. This study showed that for a better performance of weaned young lambs during summer–autumn, it is important to maintain tropical swards at a short height (25 cm). However, if the grass height exceeds this condition, the use of cattle or a mower are good options to maintain the sward height. [ABSTRACT FROM AUTHOR]

Dairy producers are continuously searching for environmentally friendly and economically sustainable alternatives to increase pasture herbage yield and reduce reliance on chemical fertilisers. A possible means to reduce fertiliser reliance is the use of biostimulants. Biostimulants such as fulvic acid and bioflavonoids help to increase N uptake efficiency, thereby increasing herbage quantity and quality. The aim of this study was to determine the effects of a soil application of a carbohydrate-derived fulvic acid and bioflavonoid biostimulant on herbage yield and nutritive composition of a mixed perennial ryegrass–clover pasture. Biostimulant treatment resulted in a lower ryegrass component of the mixed sward, in both winter and summer grazing cycles. However, the nutritive composition and total herbage yield of the pasture were not significantly affected by biostimulant treatment. The treatment did show a tendency to affect total herbage yield within a season. This suggests that total herbage yield could be increased if additional N fertiliser is applied together with a biostimulant soil treatment, although further investigation is needed to confirm this postulation. Biostimulant treatments have the potential to lead to reduced fertiliser inputs on perennial ryegrass–clover pastures as they may increase nutrient uptake efficiency. [ABSTRACT FROM AUTHOR]

Background: Numerous experiments in Russia and abroad indicate that the productivity of natural hayfields and pastures is high enough only if legumes are present in the herbage. It is also of great importance to increase their productivity by applying mineral fertilizers, which often define the final productivity of the herbage. To determine the effect of organic and mineral fertilizers on the productivity of sainfoin. Methods: The main method used in the study was a field experiment combined with laboratory analysis. Measurements of plant density were carried out in the spring before each harvesting of cover crops and sainfoin. In the course of the study, phenological and morphological observations, accounting, and evaluation of the quality of sainfoin were carried out. The structure of the herbage was evaluated according to the following indicators: plant density, plant height, leafiness, and the area of the assimilation surface of grasses. Measurements were carried out in spring before each harvesting of grasses. Height measurements were based on the phases of plant development. Results: Final yield data show that fertilizers have a significant impact. Thus, the yield of sainfoin and cover crops in 2019 (in the first year of the experiment) was: 4.7 t/ha for variant 8 and 4.5 t/ha for the control variant. In 2020 and 2021, the yield of experimental variant 8 exceeded that of the control variant. Statistical processing of the results of the experiment confirms the positive effect of fertilizers on the yield. Conclusions: The best results were achieved with the use of 30 t/ha of organic fertilizers + N60 P60 K40. [ABSTRACT FROM AUTHOR]

For the rational use of degraded pastures and the fight against desertification, it is necessary to apply phytomelioration of territories more widely. The most effective will be the use of communities consisting of shrubs, semi-shrubs and perennial grasses. To identify on this further, the study was conducted at the experimental sites of the Agroecology Research Center of the Russian Academy of Sciences in the period from 2019 to 2022. In this study, artificially created models of long-term pasture ecosystems were utilized. In the arid conditions of the south of Russia, weather conditions had the greatest impact on the productivity of the created pasture models (share of influence is 81-85%), while the yield of dry fodder mass of the herbaceous-semi-shrub layer varied from 1.2 to 3.9 t/ha, depending on the seasonality of the pasture and the composition of the soil substrate. The highest yield of phytomass is formed on pastures created on a chernozem-like sandy loam substrate (humus horizon of chernozem-like sandy loam soil) on spring-summer pastures, the yield increase is 33% higher compared to springsummer pastures on a light chestnut sandy substrate (a product of Aeolian processing of light chestnut soil). On all types of pastures, groups of cereals were leading in terms of biomass. Analysis of the multiple regression equation between the phytomass yield of model pastures (y3), temperature (x1) and precipitation of the warm period (x2) on pastures with a chernozem-like soil substrate showed that the multiple correlation coefficient R = 0.96 - this states a close relationship between the effective indicator and two factors. The multiple determination coefficient R2 = 0.98 means that 98% of the variation in the phytomass yield level is taken into account by the regression equation and 2% is accounted for by unaccounted factors on a light chestnut sandy substrate. The moderate correlation dependence of the yield of the fodder mass of model pastures (y3) on a plot with a light chestnut sandy substrate on the temperature in the warm period (x1), the component (r=0.52) indicates a significant effect on the yield of precipitation of the warm period (x2) with r=0.94. [ABSTRACT FROM AUTHOR]

An on-farm participatory study was undertaken to assess changes over seasons on the availability, botanical and morphological composition, and nutritive value of herbage from two pastures in small-scale dairy systems in the highlands of central Mexico. One pasture (TF-33) was originally sown with tall fescue, while the second pasture (KY) was naturally invaded by Kikuyu grass; both associated with white clover and over-sown in winter with annual ryegrass. Sampling was every 28 days for a year. Variables were sward height, net herbage accumulation, soil cover, tiller density, chemical composition, and in vitro digestibility. A split-plot design was used. Sward height was greater for KY. There were no differences (p > 0.05) for herbage accumulation. TF-33 was 53% live tissue, 30% dead tissue, and 17% other plant material, whilst KY was 50% live tissue, 30% dead tissue, and 18% other plant material. TF-33 showed a higher leaf to stem proportion, while stem was higher in KY. Kikuyu grass and annual ryegrass performed better when associated with TF-33 than in KY pasture. Seasonal changes significantly affected sward height, herbage mass and net herbage accumulation, whereby TF-33 performed better than KY in winter. The multispecies association of diverse grasses and legumes may be complementary at different times of the year due to plasticity among species, and is a feasible option for small-scale dairy systems. [ABSTRACT FROM AUTHOR]

Much of deforested Amazonia is dominated by pastures planted with exotic Urochloa (syn Brachiaria) grass, containing interspersed, ruderal Babassu palm (Attalea speciosa). This two‐species system offers the opportunity to investigate how two very competitive species interact. We investigated three monospecific Urochloa pastures containing dispersed Babassu palm clusters in the eastern periphery of Amazonia. We mapped 0‐ to 50‐cm Babassu and Urochloa root profiles at three distances representing contrasting relative dominance: "within clusters" (0.4–0.6 m from adult palm, Babassu‐dominated), "close" (2.5–4.0 m), and "far" (>8.0–10.0 m, Urochloa‐dominated). Total Babassu root share count was 76.0% within Babassu clusters, as opposed to Urochloa root share count (80.0%) far from clusters, confirming our experimental dominance gradient. Babassu and Urochloa root diameter composition differed strongly, whereas 44.6% of all Babassu roots were mid‐diameter or coarse; 83.0% of all Urochloa roots were fine graminoid. Vertical root profiles likewise differed: Babassu coarse and mid‐diameter roots concentrated within clusters at 20–50 cm depth, well protected against disturbance, though Babassu mid‐diameter roots did extend up to 10 m, indicating active foraging at long distances. By contrast, Urochloa mid‐diameter and coarse roots concentrated in the topsoil (70.4% in top 20 cm). Notably, 45.0% of all Urochloa fine roots but only 29.3% of deeper rooting Babassu concentrated in the top 0–10 cm. Both Urochloa mid‐diameter (R = 0.49) and fine roots (R = 0.40) correlated positively with Urochloa aboveground biomass. Fine‐root fine‐scale variability was high, with high‐density hotspots of both species in the topsoil. Babassu vertical root profiles were unaffected by the degree of interspecific competitive confrontation, whereas Urochloa fine roots were significantly shallower within than outside of Babassu clusters. Though differing Babassu and Urochloa vertical root profiles do support the notion of niche expansion caused by Babassu clusters within the vast Urochloa pastures throughout Amazonia, we also find a strong horizontal and vertical niche overlap with no indication of fine‐scale root segregation, indicating direct competition between both species, possibly in a dynamic state of "mutual invasability." In practical terms, our findings call for the diversification of Amazonian pastures beyond this two‐species system in order to increase productivity and ecological efficiency. [ABSTRACT FROM AUTHOR]

Pasture management is an important topic for dairy farms with grazing systems. Herbage mass (HM) is a key measure, and estimations of HM content in pastures allow for informed decisions in pasture management. A common method of estimating the HM content in pastures requires manually collected grass samples, which are subjected to laboratory analysis to determine the dry matter (DM) content. However, in recent years, new methods have emerged that generate digital data and aim to expedite, facilitate and improve the measurement of HM. This study aimed to evaluate the accuracy of a rising plate meter (RPM) tool in a practical setting to estimate HM in Austrian pastures. With this study, we also attempted to answer whether the tool is ready for use by farmers with its default settings. This study was conducted on the teaching and research farm of the University of Veterinary Medicine in Vienna, Austria. Data were collected from May to October 2021 in five different pastures. To evaluate the accuracy of the RPM tool, grass samples were collected and dried in an oven to extract their DM and calculate the HM. The HM obtained from the grass samples was used as the gold standard for this study. In total, 3796 RPM measurements and 203 grass samples yielding 49 measurement points were used for the evaluation of the RPM tool. Despite the differences in pasture composition, the averaged HM from the RPM tool showed a strong correlation with the gold standard (R2 = 0.73, rp = 0.86, RMSE = 517.86, CV = 33.67%). However, the results may not be good enough to justify the use of the tool, because simulations in economic studies suggest that the error of prediction should be lower than 15%. Furthermore, in some pastures, the RPM obtained poor results, indicating an additional need for pasture-specific calibrations, which complicates the use of the RPM tool. [ABSTRACT FROM AUTHOR]

Knowledge about individual daily herbage dry matter (DM) intake (DMI) helps identifying efficient dairy cows and adapting supplementation better to herbage intake and nutrient requirements of grazing dairy cows. With the aid of behavioural characteristics, raw data recorded with the RumiWatch (RW) system and processed with the RW converter 0.7.3.31 (C31), estimation of herbage DMI may be possible. First, C31, which allows differentiation of prehension bites and mastication chews, was validated through direct observation of behavioural characteristics and compared to the previous RW converter 0.7.3.11 (C11). Further, the influence of a low and high pre‐grazing herbage mass (HM), with the same target herbage allowance (HA), on bite mass, DMI, number of prehension bites, and milk production was investigated. In total, 24 lactating Holstein cows were pairwise allotted to one of two HM treatments. The cows received a new pasture paddock twice per day with a daily target HA of 22 kg DM per cow/day. On average, low HM (LHM) and high HM (HHM) paddocks had an HM of 589 and 2288 kg DM/ha, respectively, above 6.7 click units (1 CU = 0.5 cm). Overall, LHM cows produced 2.7 kg/day more milk and 2.5 kg/day more energy‐corrected milk, had the same herbage DMI and a similar prehension bite mass. The averaged bite mass per week was 0.49 g DM/bite (LHM) or 0.47 g DM/bite (HHM), respectively. A longer eating time (617 vs. 559 min/day) and a shorter rumination time (297 vs. 365 min/day) were observed for the LHM cows compared with the HHM cows. The validation of the RW showed similar results for C11 and C31 apart from prehension bites, where C31 showed a mean absolute deviation of 12.4%. Pre‐grazing HM had no effect on relevant behavioural characteristics for prospective intake estimation, namely, bite mass and number of prehension bites. [ABSTRACT FROM AUTHOR]

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This study aimed to evaluate the forage mass and nutritional value (NV) of Guinea Massai grass (Megathyrsus maximus × Megathyrsus infestum) in an open pasture (OP) or the silvopastoral system (SPS) at different stages of development (SDs). The experimental design was completely randomized, with five replications. The treatments were distributed in a factorial scheme 2 × 4, corresponding to types of systems (OP and SPS) and four SD (vegetative stage—S1, pre-flowering—S2, full flowering—S3 and maturity after flowering—S4). There was no interaction of the system × stage of plant development in any of the variables evaluated. The production of forage mass and Guinea Massai grass morphological components did not differ (p > 0.05) between SPS and OP. However, they differed between the SDs (p ≤ 0.05), with an increasing linear effect for forage mass, percentage of the stem, and dead material, and decreasing for leaf percentage and leaf: stem ratio. Only protein content differed (p < 0.05) among the chemical composition variables between culture systems. The shading caused by the SPS did not decrease the forage mass, NV, and in vitro dry matter digestibility of Guinea Massai grass compared to the system in OP. The advance of the SD of Guinea Massai grass increases the forage mass, with higher proportions of morphological components of low NV, such as stem and dead material. Silvopastoral system of Guinea Massai grass and eucalyptus is effective to prolongate the grazing season, with a greater amount of green leaves in the sward and better NV, without compromising herbage mass production in the forage growing season. [ABSTRACT FROM AUTHOR]

This study monitored spatiotemporal variation in aboveground biomass of a paddock (1.1 ha) in a sown tropical grass pasture under cattle grazing over a 22‐year period (1995–2016) by nondestructively estimating biomasses of 182 fixed locations (0.5 × 0.5 m each) in the paddock at about monthly intervals during the annual stocking season (May to October or November). The mean aboveground biomass of the paddock varied seasonally and interannually between 33 and 605 g DM/m2 and was explained by a regression model including positive effects of mean air temperature, N fertilizer rate and total precipitation during the preceding 60 days (R2 = 0.311, P < 0.001). The coefficient of variation of aboveground biomass, as an indicator of spatial (within‐paddock) variability, varied seasonally and interannually between 0.16 and 0.94, and was described by a model incorporating a positive effect of cumulative stocking density during the preceding 40 days and negative effects of mean air temperature, total precipitation during the preceding 20 days and N fertilizer rate during the preceding 60 days (R2 = 0.277, P < 0.001). The spatial distribution pattern of aboveground biomass in the paddock was persistent (P < 0.05) or not persistent over the study period, almost without being reversed. In detail, patterns in the mid stocking season tended to maintain mutual similarity in the entire range of the intervals between the measurements (364–7,694 days), whereas those at the beginning and near end of the stocking season lost mutual similarity as the interval increased. There was no indubitable evidence that the changes in botanical composition destabilized the spatial distribution pattern of aboveground biomass. The results indicate the need for assessing how the long‐term stability of the within‐paddock distribution pattern of aboveground biomass affects agronomic and ecological performance of the grazing system. [ABSTRACT FROM AUTHOR]

A two‐year experiment assessed herbage production and above‐ and below‐ground characteristics of a highly productive monoculture ('BRS Zuri' guineagrass [Panicum maximum Jacq.]) and two mixtures of three grasses (Mixture 1: 'BRS Zuri' guineagrass, 'BRS Xaraés' palisadegrass [Brachiaria brizantha Stapf.], and 'Basilisk' signalgrass [Brachiaria decumbens Stapf.]; Mixture 2: 'BRS Quênia' guineagrass [Panicum maximum Jacq.], 'Marandu' palisadegrass [Brachiaria brizantha Stapf.], and 'BRS Paiaguás' palisadegrass [Brachiaria brizantha Stapf.]), cultivated in the Brazilian tropical savanna. Mixtures 1 and 2 were subjected to two grazing intensities (removal of 40 or 60% of pre‐grazing height) and 'BRS Zuri' guineagrass monoculture was defoliated to a single grazing intensity of 50%. Treatments were randomly assigned to fifteen 0.25‐ha plots and managed under intermittent stocking by cattle. Herbage accumulation rate was similar among pastures and years (p >.1). The root mass in the tussocks did not differ (p >.1), with mean values ranging between 0.62 to 1.81 kg DM m−2. Root density in the tussock interspaces was greater in the mixtures (p <.001), regardless of seasons (p =.405) and years (p =.292). The mixtures were dominated by guineagrass (70%) and palisadegrass (30%) at the end of the experiment, with the population of 'Basilisk' and 'BRS Paiaguás' being completely suppressed throughout the experimental period. Mixing guineagrass and brachiariagrasses can be an alternative to the traditional pastoral systems in the tropics, as it does not compromise herbage production and presents a capacity to produce more roots than a very productive monoculture of 'BRS Zuri' guineagrass. [ABSTRACT FROM AUTHOR]

Studies of the photosynthetic activity of perennial grass mixtures allow for describing the peculiarities of the formation of perennial grass species forage productivity in the dry steppe zone. The study aimed to evaluate the cumulative effect of perennial cereal and legume grasses as part of complex grass mixtures on photosynthetic activity, productivity, and nutritional value of mowing and grazing phytocenoses. Adapting multicomponent grass created from various species of perennial grasses to the continental climate of the steppe zone of Northern Kazakhstan commenced, capable of resisting biotic and abiotic stresses due to biological characteristics and positively influencing other species in the phytocenoses. The study determined photosynthetic activity, the yield of green and dry masses, dry matter content, crude protein, metabolizable energy of natural pasture, single-species sowing of awnless brome, and multicomponent grass mixtures. The communal herbage obtained as a result of the study contained a large amount of crude protein (20.6%-24.7%), crude fat (2.0%-4.2%), crude fiber (18.0%-22.7%), crude ash (7.1%-7.7%), and nitrogen-free extractive substances (35.0%-44.1%). The results further enunciated that the perennial grass herbage in question had an average photosynthetic potential of 1,450,330 m²xday ha-1 in single-species awnless brome crops, while in grass mixtures the said potential was higher, ranging from 1,510,250 to 1,815,250 m²xday ha-1. The authors concluded that it was necessary to create mowing and grazing fields composed of productive and stable perennial grass mixtures on degraded pasture lands to increase available forage for farm animals and improve the system's resistance to adverse conditions. [ABSTRACT FROM AUTHOR]

Information on fungal seed-borne diseases on main pasture grasses and legumes from the literature was reviewed. These diseases reduce biomass production, quality of forage, and persistence due to progressive plant mortality. The main fungal pathogens associated with forage seeds belong to the orders Hypocreales, Pleosporales, and Helotiales in the phylum Ascomycota. Hypocreales includes the genus Fusarium, which reduces seedling establishment, and contaminates plant tissues with mycotoxins. Pleosporales includes many genera associated with seeds of legumes (Leptosphaerulina and Ascochyta), grasses (Bipolaris, Pyrenophora, Curvularia, Drechslera, Alternaria, Exserohilum, and Phoma), and both (Stemphylium). Some fungal genera within this order induce the accumulation of coumestans (leafspot-producing fungi) or produce secondary metabolites that contaminate tissues (Alternaria). Within Helotiales, the main genera are Sclerotinia (affecting mainly legumes), Clarireedia and Gloeotinia (affecting grasses). Pyricularia (order Magnaporthales), Colletotrichum (order Glomerellales), and Cercospora (order Mycosphaerellales) also include seed-borne fungi that provoke diseases on forage species as well as Rhizoctonia (order Cantharellales) and Ustilago (order Ustilaginales) which belong to the phylum Basidiomycota. These pathogens affect pastures by (i) compromising seedling establishment at early stages and (ii) constraining growth by reducing yield and seed quality at later stages. Future research should address (i) generation of reliable data on forage yield loss due to seed-borne diseases, (ii) assessment of the interaction between seed-borne pathogens and other biotic and/or abiotic stresses, (iii) delve into the study of the role of wild and/or cultivated forage species as inoculum reservoirs of pathogens, and (vi) shed light on the contamination issue due to mycotoxins generation. [ABSTRACT FROM AUTHOR]

Background: The implementation of polyphytic pastures composed of grasses and legumes is an important component of agricultural systems in temperate zones, since grazing pastures which can reduce feed costs--are a viable option for small-scale dairy systems (SSDS). Objective: To evaluate the continuous grazing of dairy cows in Festulolium pastures associated with annual and perennial ryegrass and with clover in two farmrs. Methodology: Two experiments were carried out. The first experiment was established in the municipality of Almoloya of Juárez using eight cows that were divided into two groups of four; the cows grazed on two pastures with Festulolium associated with annual ryegrass and they were fed with 3.6 kg DM/cow/day of commercial concentrate, for 16 weeks. The second experiment was carried out in the Northwest of State of Mexico; six multiparous cows grazed on two pastures, under a cross over design arrangement; one pasture features Festulolium cv Spring Green and the other, annual ryegrass. Milk and body condition ere measured every 3 and 12 d, respectively. Variables from both experiments were analyzed using a split-plot experimental design. Results: Neither experiment recorded significant differences for the net accumulation of forage, the height of the pastures, and their chemical composition (P=0.05). No significant differences between treatments (P=0.05) were recorded regarding the yields and chemical composition of the milk. Study Limitations/Implications: The study of mixed pastures can be an alternative for feeding grazing cows, helping to reduce costs in SSDS. Findings/Conclusions: Festulolium/annual ryegrass pastures with white clover are a viable forage alternative for small-scale dairy systems. [ABSTRACT FROM AUTHOR]

Practice shows that strip overseeding increases the yield of grasses by 1.5-1.9 times. However, the existing combined implements do not provide the required quality of tillage or sowing. The aim of the work was to improve the quality of soil preparation in the strip for seeding and sowing grass seeds in the northern region of the Republic of Kazakhstan. The strip overseeding implement (OPP-2) steadily performs the technological process, however, on soils with a hardness of more than 5 MPa, agricultural requirements for the width of the loosened strip and the uniformity of the incorporated grass seeds in depth are not fulfilled. This is due to the shortcomings in the technological scheme and design of the rolling-seeding tillage tool. To achieve this aim, the technological scheme of the implement was improved and three variants of the combined tillage tool were developed. The obtained experimental data showed that the implement with an improved technological scheme performs a technological process with the quality corresponding to agricultural requirements. [ABSTRACT FROM AUTHOR]

The use of grazing management strategies can influence canopy structure and the permanence of legumes. The objective of this work was to evaluate the determination of forage canopy heights as a grazing management strategy regarding herbage mass composition and tiller population dynamics in multispecies pastures comprising Megathyrsus maximus cv. Aruana and the legumes Macrotyloma axillare, Calopogonium mucunoides and Stylosanthes spp. Four treatments, defined by canopy heights of 15, 30, 45 and 60 cm, were evaluated in a randomised block design with four replications. The evaluations were performed under continuous stocking with sheep. Taller pastures (45 and 60 cm) contained greater (P < 0.05) total herbage mass of Aruana leaves and stems and also higher mass of legumes than smaller pastures (15 and 30 cm). The grass tiller population density was different between heights (P < 0.05) of 2.71, 2.02, 1.97 and 1.47 tillers/m2 for heights of 15, 30, 45 and 60 cm, respectively. The tiller appearance rate was highest in tall pastures (P < 0.05) and the lowest rate and stability index were found in 15 cm pastures. Aruana guineagrass and forage legumes can be managed in the height range of 30–60 cm under continuous stocking. [ABSTRACT FROM AUTHOR]

Aphids are major pests of cereal and pasture grasses throughout the world, vectoring disease and reducing plant production. There are few control options other than insecticides. Epichloë endophytes that produce loline alkaloids in their hosts provide a possible mechanism of control, with both meadow fescue and tall fescue naturally infected with loline-producing endophytes showing a resistance to Rhopalosiphum padi. We screened Elymus spp. naturally infected with endophytes that produced loline alkaloids at concentrations known to affect aphids on fescue but found no effect on these insects infesting Elymus. A synthetic loline-producing endophyte association with rye also had no effect on the aphids. After hypothesizing that the lolines were being translocated in the xylem in Elymus and rye rather than the phloem, we tested the rye and meadow fescue infected with loline-producing endophytes against a xylem feeding spittlebug. The endophyte in rye inhibited the feeding of the insect and reduced its survival, whereas the endophyte-infected meadow fescue had no effect on the spittlebug but reduced the number of aphids. Lolines applied to the potting medium of endophyte-free and endophyte-infected rye, ryegrass, and tall fescue resulted in a decrease in the aphid populations on the endophyte-free pasture grasses relative to the untreated controls but had no effect on aphid numbers on the rye. We tentatively conclude that lolines, produced in both natural and synthetic association with Elymus and rye, are partitioned in the xylem rather than the phloem, where they are inaccessible to aphids. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pasture dieback is a syndrome of unknown cause affecting grasses in Australia, creating significant economic losses to farmers by reducing available livestock feed and paddock carrying capacity. RC3 is a commercial plant growth stimulant tri-sodium salt of trimercapto-S-triazine (TMT) and potassium humate as active ingredients. TMT is commonly used for soil and wastewater remediation by capturing and binding heavy metals, while potassium humate is an organic compound used as a plant growth promoter. We investigated the ability of RC3 to restore soil health and productivity under pasture dieback conditions. RC3 was applied on pasture dieback affected paddock replicate plots once, at a rate of 4 mL/m2, and soil core samples were taken weekly to analyse microbial communities. Plants were collected regularly to measure dry matter and plant morphometrics. Twenty weeks after a single application, dry matter increased in RC3 plots by 900 kg/ha compared to control plots, and at week 48, eleven months after the single application, RC3 plots showed a trend of more grass and dicot species than the control. Morphometric measures suggest minor improvements in dicotyledon plants. Alpha diversity did not change with the application of RC3. Temporal correlation analysis shows that RC3 steadily reduced the presence of genera predominant in poor soils and with extreme environmental conditions over time and prevented the decline of beneficial genera, such as Marmoricola, Actinomadura, Dactylosporangium, and mle1-7. [ABSTRACT FROM AUTHOR]

Across much of the eastern United States, tall fescue [TF; Schedonorus arundinaceus (Schreb.) Dumort.], a cool‐season (i.e., C3) perennial grass, is the primary forage for pasture systems, thereby leaving producers vulnerable to reduced summer forage production and drought. Warm‐season (i.e., C4) forages can complement existing production systems by supplementing summer forage production and drought resiliency. Therefore, our objective was to compare five, C4 forage options in a grazing trial: switchgrass (SW; Panicum virgatum L.), eastern gamagrass (EG; Tripsacum dactyloides L.), a big bluestem (Andropogon gerardii Vitman) and indiangrass (Sorghastrum nutans L. Nash) blend (BBI), bermudagrass (BG; Cynodon dactylon L. Pers), and crabgrass (CG; Digitaria sanguinalis L. Scop.). Research was conducted 2014–2016 at two locations in Tennessee. Weaned beef heifers (237–242 kg initial weight) grazed 1.2‐ha pastures with three replications per species and location. Average daily gains (kg d−1) (0.62 [BBI], 0.41 [BG], 0.44 [CG], 0.42 [EG], 0.51 [SW]), grazing days (d ha−1) (412 [BBI], 459 [BG], 455 [CG], 664 [EG], 617 [SW]), and total gain (kg ha−1) (259 [BBI], 186 [BG], 200 [CG], 276 [EG], 315 [SW]) all varied among forages (P <.001). Similarly, forage nutritive values differed (P <.001) among forages: season‐long crude protein ranged from 94 (BG) to 115 (CG and EG) g kg−1, neutral detergent fiber (NDF), 601 (CG)–680 (SW) g kg−1, and acid detergent fiber (ADF) 379 (BG)–417 (EG) g kg−1. These forage options should be evaluated in the context of TF pastures to establish a broader understanding of their contribution within an overall forage system. Core Ideas: The C4 grasses provide a beneficial complement to C3‐dominated pasture systems.Native grasses tended to have greater rates of gain and grazing days than bermudagrass or crabgrass.Overall, rates of gain for the forages in this study were lower than in comparable studies.Native grasses had greater total gain per hectare than bermudagrass or crabgrass.Bermudagrass and crabgrass provided more grazing days during late summer than native grasses. [ABSTRACT FROM AUTHOR]

The bromatological analysis of pastures takes on great importance because these are the main source of food for livestock systems in Norte de Santander and in general in the country. The aim of this study was to carry out a bromatological characterization of pastures in six municipalities of Norte de Santander and thus know the productive potential of the department. Ten forage species with average ages between 29 and 47 days were evaluated to determine if there were differences in the nutritional composition of these forage species in the six municipalities of interest. Crude protein, ethereal extract, ash, lignin, cellulose, hemicellulose, FDN, FDA, macro and micronutrient content and energy assessment were evaluated. It was found that the forage species and the municipality where they develop, influence the vast majority of the nutritional quality parameters evaluated. Kikuyo grass presented the highest averages for PC (12.84 %) and ash (11.96 %), Maralfalfa grass presented the highest average values of energy (ENL = 1338.66 kcal / kg, ENM = 1434 kcal / kg and ENG = 713.66 kcal / kg) and in relation to the municipality, Pamplona presented the highest mean values of PC (12.84%) and ash (11.96%) and Chinácota presented the highest average values for energy (ENL = 1390.03 kcal/kg, ENM = 1495 kcal/kg and ENG = 774.38 kcal/kg). It was possible to recognize the values of nutritional quality, energy contents, macro and micronutrient contents associated with the predominant pastures in the 210 farms of the six municipalities of Norte de Santander, finding that the vast majority of bromatological variables of the pastures are influenced by the type of species and the area where they develop. [ABSTRACT FROM AUTHOR]

Waterlogging tolerance of eight C4 and seven C3 perennial forage grasses was reviewed. The median waterlogging duration was similar between species' type, ranging between 18 and 21 days. Inter- and intra-species variability was found in shoot and root biomass in response to waterlogging. Urochloa brizantha (C4), Brachiaria hybrid (C4) and Dactylis glomerata (C3) were the less tolerant species to waterlogging (shoot biomass median of 45%, 53% and 80% of controls), while U. humidicola (C4), Paspalum dilatatum (C4), Festuca arundinacea (C3) and Lolium perenne (C3) were the most tolerant (shoot biomass median of 97%, 101%, 87% and 94% of controls). A similar ranking of responses was found among species for root biomass. The formation of aerenchyma/root porosity (a key trait for waterlogging tolerance) was evaluated mainly in U. humidicola and P. dilatatum (C4 waterlogging-tolerant species), which showed considerable constitutive porosity (13% and 32%) and final values of 30% and 41% under waterlogging. Net photosynthesis and stomatal conductance as typical leaf physiological responses matched species' waterlogging tolerance, with the impact of hypoxia higher in C3 than in C4 species. Gaps in knowledge about waterlogging tolerance in forage grasses are: (i) additional studies on C3 perennial grasses for temperate pasture areas prone to waterlogging, (ii) identification of traits and responses aiding plant recovery after waterlogging (and also during the stress), (iii) reassessment of waterlogging tolerance considering plant developmental stage (e.g. adult vs young plants), and (iv) evaluation of sequential (i.e. waterlogging − drought) and combined (i.e. waterlogging + salinity) stresses, which often co-occur in pasture lands. The frequency and magnitude of floods are increasing in many pasture lands. In this context, this review aimed to quantitatively summarise all available information in the international literature related to waterlogging tolerance of perennial C4 and C3 forage grasses in worldwide use. This review reveals gaps in knowledge to guide future research aimed at improving forage production in areas prone to flooding. [ABSTRACT FROM AUTHOR]

Traditional Nitrogen (N) fertilization practices for tropical perennial grass are still based on annual amounts, following flat N rates instalments. This strategy does not consider variations in climatic conditions along the growing season, their impacts on the plant's demand and the soil N availability. At regrowth cycles where the amount of soil N released from mineralization or through animal excreta surpass the plant's demand, most of the N may be lost (as ammonia, nitrate, and nitrous oxide), increasing production costs and environmental pollution. This paper examines current N fertilization and discusses possible gaps in knowledge for the definition of more precise fertilization guidelines in pasture-based livestock systems based on tropical perennial grasses. More precise fertilization practices, based upon site and seasonal-specific recommendations, will substantially contribute to the establishment of best fertilization guidelines. Sustainable approaches can be defined by combining the identification of regrowth cycles where high N rates are required, with enhanced efficiency fertilizers, and/or using grass species with the potential for biological nitrification inhibition. The lack of information on tropical grasses requirements, and soil and climatic factors driving the N fate into the mineralization and immobilization processes and how these factors affect plant's N demand, still prevents opportunities for tactical applications and the establishment of best management guidelines. [ABSTRACT FROM AUTHOR]

Exploring improved tropical forages is considered to be an important approach in delivering quality and consistent feed options for dairy cattle in tropical and subtropical regions. The present study aimed to study the suitability of three improved tropical grasses, Chloris gayana 'Rhodes grass cv. Reclaimer' (RR), Megathyrsus maximus 'Gatton Panic' (GP), and Brachiaria ruziziensis x B. decumbens x B. brizantha 'Brachiaria Mulato II' (BM) evaluating their carbon assimilation, canopy structure, herbage plant–part accumulation and quality parameters under irrigated conditions. An experiment was conducted at Gatton Research Dairy (27°54′ S, 152°33′ E, 89 m asl) Queensland, Australia, which has a predominantly subtropical climate. Photosynthesis biochemistry, canopy structure, herbage accumulation, plant part composition, and nutritive value were evaluated. Photosynthesis biochemistry differed between pasture species. Efficiency of CO2 assimilation was highest for GP and quantum efficiency was highest for BM. Pasture canopy structure was significantly affected by an interaction between pasture species and harvest. Forage biomass accumulation was highest in GP, while BM produced more leaf and less stem compared to both GP and RR. A greater leafy stratum and lower stemmy stratum depth were observed in the vertical sward structure of BM. Brachiaria Mulato II showed greater carbon partitioning to leaves, leaf: stem ratio, canopy, and leaf bulk density. It also demonstrated greater nutritive value (Total digestible nutrients (TDN), acid detergent fibre (ADF), neutral detergent fibre (NDF), neutral detergent insoluble protein (NDICP), Starch, nonfibre carbohydrates (NFC), metabolisable energy (ME), mineral profile (Mg, P, K, Fe, Zn) and dietary cation–anion difference (DCAD) for leaf, stem, and the whole plant. Greater quantum efficiency, leaf accumulation, and nutritive value of BM observed in the present study suggest BM as an attractive forage option for dairying that warrants further research in pasture-based systems in tropical and subtropical climates. [ABSTRACT FROM AUTHOR]

Process‐based models such as the Agricultural Production Systems Simulator (APSIM) can be useful to simulate pasture growth and development. This aim of the study is to parameterise the APSIM‐Tropical Pasture model to simulate Marandu palisade grass (Urochloa brizantha cv. Marandu), irrigated and rainfed, under cut‐and‐carry management. Parameterisation was performed with experimental data collected in Piracicaba, SP, Brazil (Experiment 1: 11 growth cycles), and São Carlos, SP, Brazil (Experiment 2: 9 growth cycles). In both experiments, aboveground live biomass, leaf, stem, crown and dead material mass, specific leaf area (SLA), leaf area index (LAI) and height were assessed. In Experiment 1, soil water content was measured with a capacitance probe, at depths from 0 to 0.9 m. Calibration was performed for base temperature, light extinction coefficient and radiation use efficiency. The calibrated model proved to be accurate in simulating living biomass, leaf mass, LAI and height for all tested variables. In the irrigated system, the statistics presented values between 0.64 and 0.86 for coefficient of determination (R2), between 0.59 and 0.70 for efficiency coefficient (NSE) and between 0.88 and 0.95 for the Willmott's agreement index (d). For these same variables, in the rainfed system, R2 values ranged from 0.70 to 0.86; NSE from 0.54 to 0.70; and average d was 0.93. The simulation of soil water content showed satisfactory results for rainfed pasture, but was less precise for the irrigated treatment. The calibration of the APSIM‐Tropical Pasture model for Marandu palisade grass resulted in efficient simulations of pasture growth under cut‐and‐carry management. [ABSTRACT FROM AUTHOR]

Copyright of Tropical Grasslands / Forrajes Tropicales is the property of International Centre for Tropical Agriculture - CIAT and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study was to evaluate the degradation properties of DM and CP of different forages in rumen of ruminants. The rumen degradation characteristics of six common pastures were analyzed by using three Dorset mutton sheep with permanent rumen fistulas as experimental animals. The results showed that the rumen real-time degradation rate of DM and CP of alfalfa was significantly higher than that of other forages (P<0.05), and the rumen real-time degradation rate of DM and CP of Leymus chinensis was the lowest. The order of DM effective degradation rate of different pastures was alfalfa > Satawang > oat grass > Foxtail> elephant grass > Leymus chinensis, and the order of CP effective degradation rate was alfalfa > Satawang > elephant grass = oat grass > Foxtail > Leymus chinensis. The study indicates that the degradation rate of the legumes alfalfa and Satawang in rumen is higher than that of elephant grass, oat grass, Foxtail and Leymus chinensis. [ABSTRACT FROM AUTHOR]

Carbon allocation determines plant growth, fitness and reproductive success. However, climate warming and drought impacts on carbon allocation patterns in grasses are not well known, particularly following grazing or clipping. A widespread C3 pasture grass, Festuca arundinacea, was grown at 26 and 30°C in controlled environment chambers and subjected to drought (65% reduction relative to well‐watered controls). Leaf, root and whole‐plant carbon fluxes were measured and linked to growth before and after clipping. Both drought and warming reduced gross primary production and plant biomass. Drought reduced net leaf photosynthesis but increased the leaf respiratory fraction of assimilated carbon. Warming increased root respiration but did not affect either net leaf photosynthesis or leaf respiration. There was no evidence of thermal acclimation. Moreover, root respiratory carbon loss was amplified in the combined drought and warming treatment and, in addition to a negative carbon balance aboveground, explained an enhanced reduction in plant biomass. Plant regrowth following clipping was strongly suppressed by drought, reflecting increased tiller mortality and exacerbated respiratory carbon loss. These findings emphasize the importance of considering carbon allocation patterns in response to grazing or clipping and interactions with climatic factors for sustainable pasture production in a future climate. Summary Statement: Drought and warming differentially affect carbon partitioning above and belowground in a pasture grass, Festuca arundinacea, and reduce biomass and productivity. Combined drought and warming treatments amplify carbon loss. Clipping during climate extremes, particularly drought, reduces regrowth. [ABSTRACT FROM AUTHOR]

Simple Summary: Globally, tropical pasture species predominate in tropical and subtropical climates, and are the primary feed source for grazing livestock including dairy cattle. Therefore, this study aimed at systematically analysing the nutritive values of tropical pastures and the implications of potential methane gas production from tropical pasture species and livestock, in relation to the growing conditions and agronomic management approaches used (defoliation frequency and intensity) across different climates. This analysis allowed us to understand the better performing tropical pasture species grown across wider geographical regions, in order to improve pasture-based livestock production systems. Results revealed that pasture quality and methane gas production varied among and within species, and were significantly affected by the climate and by the agronomic management regime as well. The demand for dairy products is ever increasing across the world. The livestock sector is a significant source of greenhouse gas (GHG) emissions globally. The availability of high-quality pasture is a key requirement to increase the productivity of dairy cows as well as manage enteric methane emissions. Warm-season perennial grasses are the dominant forages in tropical and subtropical regions, and thus exploring their nutritive characteristics is imperative in the effort to improve dairy productivity. Therefore, we have collated a database containing a total of 4750 records, with 1277 measurements of nutritive values representing 56 tropical pasture species and hybrid cultivars grown in 26 different locations in 16 countries; this was done in order to compare the nutritive values and GHG production across different forage species, climatic zones, and defoliation management regimes. Average edaphoclimatic (with minimum and maximum values) conditions for tropical pasture species growing environments were characterized as 22.5 °C temperature (range 17.5–29.30 °C), 1253.9 mm rainfall (range 104.5–3390.0 mm), 582.6 m elevation (range 15–2393 m), and a soil pH of 5.6 (range 4.6–7.0). The data revealed spatial variability in nutritive metrics across bioclimatic zones and between and within species. The ranges of these nutrients were as follows: neutral detergent fibre (NDF) 50.9–79.8%, acid detergent fibre (ADF) 24.7–57.4%, crude protein (CP) 2.1–21.1%, dry matter (DM) digestibility 30.2–70.1%, metabolisable energy (ME)3.4–9.7 MJ kg−1 DM, with methane (CH4) production at 132.9–133.3 g animal−1 day−1. The arid/dry zone recorded the highest DM yield, with decreased CP and high fibre components and minerals. Furthermore, the data revealed that climate, defoliation frequency and intensity, in addition to their interactions, have a significant effect on tropical pasture nutritive values and CH4 production. Overall, hybrid and newer tropical cultivars performed well across different climates, with small variations in herbage quality. The current study revealed important factors that affect pasture nutritive values and CH4 emissions, with the potential for improving tropical forage through the selection and management of pasture species. [ABSTRACT FROM AUTHOR]

High growth rates and rapid reproductive development and associated decline in feed quality of sown tropical perennial grass pastures present management challenges for livestock producers. Conservation of surplus forage as silage could be an effective management tool. Experiments were conducted to evaluate the fermentation quality of silages produced from tropical grasses. Five species (Chloris gayana, Megathyrsus maximus, Panicum coloratum, Digitaria eriantha and Cenchrus clandestinus) were ensiled without additives after a short, effective wilt at dry matter (DM) contents ranging from 302.4 to 650.1 g kg−1. The fermentation profile of all silages in 2019 was typical for high DM silages, but in 2020 ammonia (% of total nitrogen: NH3-N), acetic acid and pH levels were higher. In 2020 M. maximus (302.4 g kg−1 DM) was poorly preserved with 20.2% NH3-N. The DM content of all other silages exceeded 350 g kg−1 and fermentation quality was generally good. In a second experiment, M. maximus was ensiled at 365 g kg−1 chopped and 447 g kg−1 DM chopped and unchopped, either without or with Pioneer 1171® (Lactobacillus plantarum and Enterococcus faecium) or Lallemand Magniva Classic® (L. plantarum and Pediococcus pentasaceus) bacterial inoculant. Inoculants increased lactic acid production, reduced pH and improved fermentation compared to Control, but D-lactate, L-lactate and acetic acid production differed between inoculants. Unchopped silages had higher pH and NH3-N and better preserved protein fraction than chopped silages at the same DM content. In both experiments, wilting increased water soluble carbohydrates by 0.5–31.5 g kg−1 DM and ensiling increased degradation of the protein fraction. We concluded that a rapid and effective wilt combined with a bacterial additive resulted in well preserved tropical grass silages. [ABSTRACT FROM AUTHOR]

Plant species show a broad spectrum of plasticity in their covarying root traits in response to soil water limitation ranging from no change to shifts towards traits that enhance water and nutrient acquisition. Knowledge of root trait correlations and associated trait plasticity under drought is crucial to sustaining grassland production, including rangelands and pastures, under future, drier climates.Here, we investigated below‐ground responses to drought in four C3 and three C4 grasses and whether these explain above‐ground responses during extreme cool‐season drought and post‐drought recovery in a well‐replicated field experiment. We hypothesised that (a) C3 and C4 functional groups differ in their below‐ground trait responses to drought: C3 species shift their traits in line with a drought avoidance strategy and C4 species shift towards drought tolerance strategies; (b) post‐drought recovery is associated with below‐ground carbon reserves in both functional groups.Root traits in the C3 functional group differed from C4 by having higher values for specific root length, nitrogen and soluble sugar concentrations, while C4 root traits were associated with higher mean diameter, tissue density and starch concentrations. Drought‐induced plasticity in root traits in both functional groups was evidenced by increased values for specific root length, soluble sugars and nitrogen concentrations, and reduced values for tissue density, which we interpret as a drought avoidance strategy. Increasing root soluble sugars in C3 and C4 grasses and lower root tissue density in C4 species under drought were associated with greater above‐ground productivity. Above‐ground biomass recovery post‐drought was predicted by root and crown soluble sugar concentrations and root longevity across both plant functional groups.These findings highlight the importance of understanding links between root trait plasticity and plant productivity during and following drought for predicting plant species' responses to changes in a future climate. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Foliar fertilizing of meadow grass stand of type Chrusopogon gryllus L. type and pasture grass stand of Nardus stricta L. type with humate fertilizer, such as Biostim (400 ml/da) increases the crude protein content in dry matter by 34.2% and 31.3%, respectively. The highest energy and fodder nutritional value is the fodder mass of the variants treated with a dose of 400 ml/da (for Chrusopogon gryllus L.) and 200 and 300 ml/da (for Nardus stricta L.). The amount of gross energy in meadow grass stands is 1.0% lower than in pastures. The efficiency of the applied biofertilizer is most pronounced in the variants with 100 ml/da dose, where the amount of dry matter and crude protein reaches 808.80 kg and 79.55 kg - for meadow and 509.60 kg and 28.79 kg - for pasture grasslands. There is no difference in the total costs (7.87 BGN/da) regarding the application of foliar fertilizers in pasture and meadow grass stands. The total revenue, total profit, profitability and critical level of the yield from the conducted agrotechnical measure in the meadow grass stands are higher by 19.9%, 25.4%, 27.7% and 92.1% respectively compared to those of the pastures, but at a lower cost price. [ABSTRACT FROM AUTHOR]

One of the main limitations for the cultivation of forages refers to seed dormancy, which can compromise the emergence of seedlings in the field and the establishment of pastures. Therefore, the objective was to evaluate the germination and vigor of buffel grass seeds cv. Aridus stored under environmental conditions. The experimental design used was completely randomized, with six evaluation periods (0, 6, 12, 18 and 24 months after harvest) and four replications. Right after the harvest, and at each evaluation period, the seeds were evaluated for water content, germination and vigor. The water content of the seeds did not differ. There were increases in the percentage of seed germination from the initial evaluation period up to 17.96 months, reaching an estimated maximum value of 62.74%. The buffel grass seeds showed progressive increases in seedling emergence and in the emergence speed index (IVE) evaluated over the storage time. It is recommended that pastures of buffel grass cv. Aridus are formed using seeds stored between 13.97 to 18.98 months under environmental conditions, as they present greater germination and vigor. [ABSTRACT FROM AUTHOR]

Grassland biomass production is strongly linked with the timing and intensity of precipitation events. While the direct effects of precipitation patterns on grasses are well‐studied, less is known regarding plant–plant interactions during different phases of drought (i.e., dry down vs. recovery). Here, we examined how the intensity and timing of drought affected biomass production, traits related to growth rate and competitive vigor (specific leaf area [SLA], leaf dry matter content [LDMC], and height [HT]), and competitive effects in three common pasture grasses. Each species was grown alone (one individual per 45‐L planter) or with competition (one individual of each species per 45‐L planter) under three different drought types: (1) "short‐term" drought where water was withheld until the first species reached stomatal closure; (2) "prolonged" drought where water was withheld until all three species reached stomatal closure; and (3) "repeated" short‐term drought where water was withheld until the first species reached stomatal closure, plants were rewatered to capacity, and then, the drought was repeated. In all three drought types, replicates were assessed for biomass and traits pre‐ and post‐rewatering to represent the "resistance" and "recovery" phases of drought, respectively. Overall, we found (1) competitive interactions during phases of drought were primarily mediated by plant HT and LDMC, not SLA; (2) the severity and frequency of drought were key factors in describing plant–plant interactions during phases of drought; and (3) interspecific differences in traits and trait responses to drought phases were key in predicting plant–plant competition. Such shifts in competition interactions associated with interspecific trait responses to drought and during recovery from drought are likely to have significant effects on the productivity and composition of multispecies, grass‐dominated plant communities. [ABSTRACT FROM AUTHOR]

The potential of tall fescue (Schedonorus arundinaceus Dumort) and orchardgrass (Dactylis glomerata L.) as stockpiled forages has been documented; however, limited information describes the characteristics of other species, especially complex mixtures of cool‐season naturalized pastures. A 3‐yr study assessed the herbage mass, forage quality, and botanical composition of mixed cool‐season naturalized pastures [orchardgrass, tall fescue, clover (Trifolium spp.), narrowleaf plantain (Plantago lanceolata L.), and quackgrass (Elymus repens [L.] Gould)] in response to two stocking rates based on daily herbage allowances of 3.5% (low) or 7.0% (high) of heifer bodyweight. The stocking rate for the entire pasture area, including unoccupied paddocks during the grazing period, was 2.4 and 1.3 heifers acre−1 for the low and high treatments, respectively. Stockpiling began in August; grazing began in early November. The initial herbage mass and botanical composition were determined at the end of the stockpiling period. Herbage samples were taken throughout the fall grazing period at intervals of 11 to 19 d. The stocking rate had no effect on changes in botanical composition. Total legume percentage increased from 6% in Year 1 to 31% in Year 3 (P <.05). Herbage mass declined more quickly in Year 3 than in Years 1 and 2 (P <.05), probably because of the high percentage of legumes. As fall grazing progressed, crude protein content and in vitro true dry matter digestibility declined, and neutral detergent fiber content increased. Mixed cool‐season naturalized pastures could be used for stockpiling and grazed intensively without detrimental effects on subsequent stockpiling periods. Core Ideas: Stocking rate did not affect botanical composition, herbage mass, or forage quality.Intensive fall grazing did not affect the herbage mass quality of later stockpiling.The proportion of clover increased across 3 yr of fall grazing regardless of the stocking rate. [ABSTRACT FROM AUTHOR]

Determining the relationship between reductions in stomatal conductance (gs) and leaf water transport during dehydration is key to understanding plant drought responses. While numerous studies have analysed the hydraulic function of woody species, minimal research has been conducted on grasses. Here, we sought to characterize hydraulic vulnerability in five widely‐occurring pasture grasses (including both C3 and C4 grasses) and determine whether reductions in gs and leaf hydraulic conductance (Kleaf) during dehydration could be attributed to xylem embolism. Using the optical vulnerability (OV) technique, we found that all species were highly resistant to xylem embolism when compared to other herbaceous angiosperms, with 50% xylem embolism (PX50) occurring at xylem pressures ranging from −4.4 to −6.1 MPa. We observed similar reductions in gs and Kleaf under mild water stress for all species, occurring well before PX50. The onset of xylem embolism (PX12) occurred consistently after stomatal closure and 90% reduction of Kleaf. Our results suggest that factors other than xylem embolism are responsible for the majority of reductions in gs and Kleaf during drought and reductions in the productivity of pasture species under moderate drought may not be driven by embolism. Summary Statement: Pasture grasses are highly resistant to xylem cavitation, with cavitation occurring consistently after significant reductions in stomatal conductance (gs) and leaf hydraulic conductance (Kleaf). Our results suggest that factors other than xylem cavitation are responsible for reductions in gs and Kleaf during moderate drought with cavitation only occurring under extreme drought conditions. [ABSTRACT FROM AUTHOR]