Herbage Quality Research Articles

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<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.

Predicted methane production from Italian ryegrass pastures with contrasting chemical composition under sheep grazing in Northern Norway

AbstractBackgroundThe Norwegian sheep farming system relies on forages, such as grass silage during winter and grazing cultivated leys and rangeland pastures during summer. Sheep and other ruminants produce enteric methane (CH4), a greenhouse gas of interest, and there is a need for reliable data on gas emissions from sheep capturing both the indoor feeding period and the grazing season. This study utilized an in vitro gas technique (with standard cow rumen fluid) and modeling approach to estimate CH4 production and fermentation patterns based on two different qualities of Italian ryegrass (Lolium multiflorum) pasture under sheep grazing.ResultsHerbage quality was examined for two 10‐day periods, in July and August. Differences in chemical composition of the herbage during these periods had an impact on herbage digestibility and CH4 production. Total gas production and CH4 levels were significantly higher for lower quality herbage grazed in July than for higher quality herbage grazed in August (p < 0.005). Production of volatile fatty acids in the rumen remained constant between the two periods, but the higher acetate to propionate (A/P) ratio correlated with the higher CH4 production.ConclusionThese findings suggest that pasture quality is an important factor to consider when implementing grazing strategies to reduce enteric CH4 production in sheep.

The effect of growth stage and cutting height of Virginia fanpetals (Sida hermaphrodita) on quality and nutrition value of herbage and silage

The effect of growth stage and cutting height of Virginia fanpetals (Sida hermaphrodita) on quality and nutrition value of herbage and silage

Herbage Quality of Eight Native Hordeum Ecotypes Collected From Natural Grassland & Pasture Ecology of Southeastern Anatolia

In this study, plant samples of eight different ecotypes of three distinct species of the genus Hordeum were collected at the anthesis stage of the plants in the 2023 spring in Southeastern Anatolia's natural grassland and pasture ecology. The quality analyses of the herbage samples of Hordeum bulbosum, H. murinum, and H. spontaneum ecotypes collected from five different locations (Karacadag-I, Batman-1, Diyarbakır-6, Diyarbakır-8, and Diyarbakır-13) were determined by NIRS analyzer. Crude protein (CP), dry matter (DM), acid detergent insoluble fiber (ADF), neutral detergent insoluble fiber (NDF), acid detergent insoluble protein (ADP), Ca, K, Mg, P, Ca/P, K/(Ca+Mg), digestible dry matter (DDM), dry matter intake (DMI) and relative feed values (RFV) were determined. The values were determined between 8.2-23.4% for CP; 92.1-93.4% for DM; 19.3-36.2% for ADF; 26.2-71.9% for NDF; 0.16-0.71% for ADP; 60.7-73.9% for DDM; 1.67-4.58% for DMI; 78.6-262.8 for RFV; 0.30-0.42% for P; 1.72-2.84% for K; 0.12-1.62% for Ca; 0.17-0.30% for Mg; 0.33-3.84 for Ca/P; 2.76-4.77 for K/(Ca+Mg). In conclusion, the CP, ADF, NDF, DMI, RFV, and Ca/P values were found very variable in collected ecotypes and can be used for forage barley breeding purposes.

Long-term evaluation of pasture production, seasonality, and variability: An application of the DairyMod pasture model for three tropical species

Adoption of improved pastures coupled with intensified management provide quality pastures in adequate quantities and thus improve livestock productivity. While pasture modelling is imperative for exploring the performance of newer pastures, models are little used for long-term simulations of multiple tropical pastures (genotype), under varying soil, climate (environment) and pasture production systems (management). We applied the DairyMod, a biophysical model to simulate the long-term pasture production of Brachiaria ruziziensis x B. decumbens x B. brizantha ‘Brachiaria Mulato II’ (BM), Megathyrsus maximus ‘Gatton Panic’ (GP), and Chloris gayana ‘Rhodes grass cv. Reclaimer’ (RR) across major dairying regions of Sri Lanka under different management scenarios and characterize the long-term pasture growth, seasonality and spatial variability, and possible implications for dairying in Sri Lanka. Simulations of three pasture species were carried out for 16 locations (8 dry (DZ), 5 intermediate (IZ), and 3 wet zone (WZ)) over 30 years (1980–2010). Three pasture management scenarios simulated were; 1) potential pasture production system under non-limiting N and irrigation (Yp) 2) rainfed pasture production system under non-limiting N fertilizer (Yw), and 3) rainfed pasture production system under current nitrogen (N) fertilizer rate (Ya). Statistical techniques were used to identify the long-term growth rates, variability, and trends in pasture production. The long-term pasture production varied greatly among climate, species, and management scenarios. Overall, the Ya showed a seasonal cycle following the rainfall pattern, with a reduction in growth rates in dry seasons (May–September). Pasture growth rates were greater in GP at Ya, and BM at Yw and Yp while RR showed the lowest growth rate at all times. Variability of pasture growth was high in DZ (May–September) and RR has the lowest growth variability. The Yw increased the growth rate (doubled) while the Yp substantially increased (nearly tripled) the growth rate and growth pattern producing less variable pastures. Simulated growth rates suggest that GP in low-input and BM in high-input farming areas would be more suitable. Our study suggested that the BM, GP, and RR are edaphic-climatologically fit for major dairying regions in Sri Lanka and the appropriate fertilizer and irrigation management can greatly increase the herbage accumulation and availability of year-round pastures. While this study offers valuable insights, the species-specific growth pattern, growth variability, yield potential under different managements and the possible implications for herbage quality need to be sensibly considered when selecting the appropriate species.

Renovation of grasslands with grass and white clover – Effects on yield and carbon sequestration

There is a pressing need to support farmers' decisions on grassland renovation, based on sound scientific evidence regarding its effects on productivity, herbage quality and soil organic carbon stocks. To quantify these effects a long-term experiment with grass/white clover swards was set up at the Lindhof research farm in Northern Germany in 1995. Treatments included control plots of undisturbed grassland as well as 10 grassland renovations starting after 10 (2005) years and repeated on different plots 10 times until 2019, and without and with addition of slurry (equivalent to 240 kg N ha−1 yr−1). Grassland renovation resulted in a significant drop in biomass production in the first year after renovation, and the slightly higher yields in the third year after renovation could not compensate for this drop. Yields from the year of renovation to three years afterwards were generally lower, with average reductions over the 4-year periods of 2600 kg DM ha−1 for the treatments without slurry and 1500 kg DM ha−1 for the slurry treatments. Differences in herbage quality between permanent and renovated grassland were negligible and generally not statistically significant. The soil organic carbon showed a rapid and significant drop in the year of renovation, followed by a gradual increase. Without slurry application, the initial levels of soil organic carbon stocks could not be reached even after a period of 18 years following renovation, and with slurry application, it took about 8–10 years. Deep ploughing to a depth of 30 cm did not increase the SOC stocks compared with the undisturbed permanent grasslands, suggesting that the topsoil has not reached the carbon saturation level. We conclude that maintaining productivity of permanent grassland without renovation measures is a promising way towards yield stability and natural climate solutions.

Utilizing treated wastewater for pasture irrigation: Effects on productivity, plant community structure and soil properties

AbstractSurplus wastewater accumulates in winter and requires a discharging solution. In our study we examined the effects of using treated wastewater (TWW) as supplemental pasture irrigation in winter. To test the effect of TWW irrigation on the vegetation and soil, 10 grazing prevention exclosures were established at Ramat‐Hanadiv Park, Israel, with half of them irrigated with TWW. Soil and vegetation were sampled during 2 years of irrigation and 1 year after cessation of irrigation. Vegetation composition, species richness, and productivity were sampled at the peak of the growing season and various indices of herbage quality were measured. Our results show that irrigation with wastewater increased herbage production by an average of 38% and total pasture protein production by 9% relative to the control subplots. Conversely, TWW irrigation decreased plant protein content while increasing herbage fibre content and lowering its digestibility. Over a period of 2 years, species richness decreased in the irrigated subplots. Most of the soil indices examined were not affected by irrigation, but in the irrigation subplots, sodium values and the sodium adsorption‐ratio were higher than in areas without irrigation. Additional resources in winter enabled the plants to grow rapidly and increased interplant competition. Changes in vegetation composition were revealed through functional group reshuffling and species richness decline. The results of our study show that wastewater irrigation causes an increase in productivity but a decrease in forage quality. At the pastoral system level, the significant increase in productivity leads to increased availability of protein and herbage for animals.

An inventory of grassland use on horse farms

Horses can contribute to the maintenance of grassland. To determine the potential contribution of grassland to horse nutrition, we investigated the seasonal variation of herbage on offer and its nutritional quality in an inventory on six practical horse farms in Central Germany during 2019. On all horse-grazed pastures compressed sward height (CSH) was measured monthly and converted into aboveground herbage (AGH) to allocated short and tall grass sward areas (area-specific) via calibration cuts. In addition, four focus pastures were selected for monthly obtained area-specific herbage quality samples. The farm-specific management was monitored using questionnaires and grazing diaries to determine underlying factors influencing herbage biomass and quality. The proportion of short grass sward areas increased during the grazing season (p=0.0010), which was related to high stocking intensity in terms of livestock unit grazing days (LUGD, p <.0001). On most farms, LUGD were constant throughout the growing season and not adjusted to changing grass growth. Herbage crude protein (CP, p=0.0038), metabolizable energy (ME, p <.0001) concentrations and acid detergent fibre in the organic matter (ADF, p <.0001) differed among the grass sward areas. The results suggest that sufficient ME (4.2 ± 0.32 – 8.4 ± 0.15 MJ ME kg−1 DM) for maintenance and pre-caecal digestible CP (pcdCP) (37.0 ± 3.86 – 77.4 ± 4.44 g kg−1 DM) could be provided during the grazing season. The study highlights the need to incentivise grassland management for herbage provision among horse owners to exploit the potential of grassland during the grazing season.

Determination of herbage quality and mineral matter in some pastures of Sivrice District of Elazig Province in Turkey

Determination of herbage quality and mineral matter in some pastures of Sivrice District of Elazig Province in Turkey

Effect of short-term grazing exclusion on herbage species composition, dry matter productivity, and chemical composition of subtropical grasslands

Abstract Grazing exclusion (GE) is a useful management technique for restoring degraded grasslands. The herbage mass productivity and chemical makeup in the grazing-excluded subtropical grassland environment has, however, received little attention. A subtropical riverine grassland was selected to determine the effect of GE on herbage mass productivity and chemical composition in Nepal. In three successive harvesting times from September to November 2020, the herbage was sampled along the six randomly selected transects of 100 m length and at two treatments (GA: Grazing-allowed and GE: Grazing-excluded plots) at three different times of harvest from a 1,000-ha grassland. A total of 108 herbage cut samples were collected from the individual 1 m × 1 m quadrats at the three harvests, respectively, from the GA and GE plots. Fences were used to maintain the GE plots to avoid grazing to prevent the vegetation altered by grazing. Day before herbage sampling, the functional groups, cover-abundance within the sampling quadrats were investigated. By cutting the fresh herbage 5 cm above the ground and subjecting it to oven drying for laboratory examination, the herbage mass productivity within each quadrat was measured. Using established laboratory procedures, the chemical analysis of herbage was evaluated for its proximate, fibre, and mineral contents. The results of the study demonstrated that GE significantly increased grass species than other-forbs, other-graminoids, and legumes, respectively, and increased dry matter productivity, which could be seen by an increase in leaf stem ratio, tiller productivity, increased coarseness (fibrous content), total ash, calcium (Ca), and phosphorus (P), but with a decreased nonstructural carbohydrate, and the concentrations of ether extract and crude protein. Research results also confirmed that GE increases herbages’ fibrousness and productivity, though the herbage quality, intake, and digestibility decline. It further demonstrates that grazing is a crucial biological component for maintaining pasture quality in subtropical grasslands and that managing grasslands through livestock grazing would make grasslands more stable and nutrient-enriched. The findings of this study can be useful in the long-term monitoring of grazing livestock in the subtropical grasslands when considering further investigations with the multiple factors in future.

The Effect of Different Forms of Titanium Dioxide on the Yield, Chemical and Microbiological Parameters of Perennial Ryegrass (Lolium perenne L.) Herbage and Silage

The aim of this study was to evaluate the applicability of three forms of titanium dioxide (TiO2) and their effect on the yield, chemical and microbiological quality of perennial ryegrass herbage and silage. Two types of titanium dioxide nanoparticles (TiO2NPs) and a commercial product, labeled here as TiO2Com, were selected for the studies. The yield and chemical parameters of herbage did not improve significantly in response to the TiO2 treatment, in comparison to the control group (CONT). The crude protein content of silage was significantly lower in the TiO2Com-treated group than in the TiO2NPs2 group (117 vs. 129 g kg−1 dry matter (DM)). The use of water-soluble carbohydrates during fermentation was limited in the TiO2NPs2 and TiO2Com groups. The fermentation pattern was similar for each investigated group, and a significant difference in pH values was noted between the TiO2NPs2 (pH = 4.49) and CONT (pH = 4.68) group. Lactic acid concentration was the highest in the TiO2NPs1 group (94.8 g kg−1 DM), and the difference relative to the CONT group (83.2 g kg−1 DM) was statistically significant. It was concluded that TiO2 and its nanoparticles have the potential to improve the physicochemical and microbiological quality of herbage and silage.

P28 Diverse pasture species treated with seaweed bio-stimulants increase herbage quality, lamb and ewe growth rates

P28 Diverse pasture species treated with seaweed bio-stimulants increase herbage quality, lamb and ewe growth rates

Tree lines do not reduce grassland productivity and herbage quality in alley cropping under drought

AbstractIn alley cropping, woody perennials are combined with agricultural crops or grassland in order to benefit from favourable interactions between trees and crops. Trees influence growth and senescence processes in grassland as well as plant chemical composition and plant water use. In a field experiment with grassland and alley‐cropped willow coppices, we analysed the impact of distance and position relative to the tree line on grassland herbage biomass, proportion of dead herbage and herbage quality in two successive growth periods of two experimental years. The experimental years were chosen so that growth periods among years showed a similar rainfall pattern. Relative ET (evapotranspiration) as defined by actual divided by potential evapotranspiration reflected the severity of water shortage with a moderately dry (relative ET ~ 0.5) first growth period with increasing dryness in the second growth period of each year. We determined bulk stomatal conductivity of the grass shoot by measuring δ13C (carbon) signatures. Stomatal conductivities were higher close to the trees in drier periods (i.e. more negative δ13C values). Herbage biomass decreased with decreasing relative ET, but showed no systematic influence of the tree line. We found that vegetation composition changed with distance to the tree line. The proportion of dead herbage was equal at all distances from the tree line under very dry conditions, but smaller close to the trees under moderately dry conditions. Herbage quality, as approximated by crude protein and ADF concentrations in live biomass, was higher closer to the tree line. We conclude that the tree line does not adversely affect grassland productivity under drought and improves the plant water status as reflected by the δ13C signature.

Effects of Variety and Seeding Rate on Performance of Sweet Lupin (Lupinus angustifolius) at Holetta, in the Central Highlands of Ethiopia

The study was executed to evaluate the agro-morphological and nutritional performance of four narrow-leafed blue sweet lupin varieties (Australian lupin, Probor, Sanabor, and Vitabor) sown with five seeding rates (60, 70, 80, 90, and 100 kg/ha) during the main cropping seasons of 2014 and 2015 at Holetta in the central highlands of Ethiopia. Randomized complete block design replicated three times in factorial arrangements was used for experimenting. The lupin varieties were sown in rows with an inter-row spacing of 30 cm. At sowing, diammonium phosphate fertilizer at the rate of 100 kg/ha was uniformly applied for all treatments in both years. Data were collected on plant height, dry matter yield, number of pods per plant, number of seeds per pod, seed yield, and nutritive value. All measured data were subjected to analysis of variance using procedures of SAS general linear model. The result revealed that plant height, number of pods per plant, and number of seeds per pod of lupin varieties were significantly (P&lt;0.001) affected by experimental years. The varietal difference was the major cause of variation (P&lt;0.05) for dry matter yield, the number of pods per plant, and seed yield. The Sanabor, Probor and Vitabor varieties had 38, 23, and 20% dry matter yield advantage over the introduced Australian lupin variety, respectively. The Sanabor variety which produced the highest seed yield had 25, 17, and 14% seed yield advantages over Vitabor, Australian lupin, and Probor variety, respectively. The seed yield performance of lupin varieties was positively correlated with the number of pods per plant while it was negatively correlated with the number of seeds per pod. The dry matter yield and number of seeds per pod were also significantly (P&lt;0.05) affected by seeding rates of lupin varieties. The dry matter yield of lupin varieties increased with increasing seeding rates indicating the tested lupin varieties had a low tillering performance. The number of seeds per pod of lupin varieties decreased with increasing seeding rates. On the other hand, the nutritive values did not differ significantly (P&gt;0.05) among the tested lupin varieties. However, Vitabor variety gave better CP and IVDMD followed by Australian lupin while Probor variety gave the lowest CP and IVDMD. Vitabor variety which exhibited better ash, CP, and IVDMD contents produced the lowest NDF, ADF, and ADL contents when compared with other varieties. Generally, Sanabor and Probor varieties had better forage dry matter yield and seed yield but Vitabor and Australian lupin had relatively better nutritive values. For forage production, lupin varieties should be sown with the highest seeding rate (100 kg/ha) while the lowest seeding rate (60 kg/ha) is recommended for seed production. However, this research should be done across locations and over years to prove the above-recommended seeding rates for forage and seed productions in the study area and similar agro-ecologies. Keywords: dry matter yield, herbage quality, plant height, pod number, seed yield, seeding rate.

Evaluation of Agronomic Attributes and Herbage Quality of Selected Trigonella Species

Evaluation of Agronomic Attributes and Herbage Quality of Selected Trigonella Species

Appropriate Water-Nitrogen Regulation Mode to Improve Productivity of Mixed-Sowing Grassland of Bromus inermis and Alfalfa

Scientific selection of appropriate herbage planting management mode is an important guarantee to promote artificial grassland development and grassland productivity. In this study, three-year-old alfalfa (Medicago sativa L.) and bromus inermis were applied to analyze the effects of planting patterns (bromus inermis and alfalfa mixed-sowing D1, bromus inermis mono-sowing D2), nitrogen application (pure nitrogen) level (N1: 60 kg·ha−1, N2: 120 kg·ha−1), and water regulation (upper and lower limits of irrigation are calculated as a percentage of field capacity θf, W1: slight water deficit 65~85% θf, W2: moderate water deficit 55~85% θf, W3: serious water deficit 45~85% θf) on herbage growth and water-nitrogen use efficiency. This research applied the principal component analysis, the TOPSIS model, and the combination evaluation to evaluate each treatment. Results demonstrated that (1) the plant height, leaf area index, and yield of mixed-sowing herbage were 81.63%, 119.52%, and 111.51%, higher than the mono-sowing herbage. Increasing the amount of irrigation and nitrogen application could enhance herbage yield. The herbage yield with the W1N2 treatment was the highest. In this treatment, the mixed-sowing herbage yield was 26,050.73 kg·ha−1, and the mono-sowing herbage yield was 12,186.10 kg·ha−1. (2) The crude protein content of mixed-sowing herbage increased by 41.44%, higher than mono-sowing herbage, and the relative feeding value decreased by 16.34%. Increasing irrigation and nitrogen application could improve the quality of herbage. Meanwhile, the quality of herbage treated with W1N2 was the best. (3) The water use efficiency (WUE), irrigation water use efficiency (IWUE), partial factor productivity of nitrogen (PFPN), and crude protein water use efficiency (CPWUE) of mixed-sowing herbage were significantly higher than mono-sowing herbage. The PFPN and the CPWUE of herbage improved with increasing irrigation amount. Meanwhile, the WUE, the IWUE, and the CPWUE of herbage also improved with increasing nitrogen application amount. The results showed that mixed-sowing of alfalfa and bromus inermis with slight water deficit (upper and lower limit of irrigation was 65~85% θf) and nitrogen application (120 kg·ha−1) could have the best comprehensive production effect. At the same time, it was a planting and management mode of high yield, high quality, and high efficiency of artificial herbage in the oasis-desert interlacing area of Hexi, Gansu Province, China, and areas with similar climates.

Grazing effects of wintering geese on grassland yield: A long‐term study from Northwest Germany

Abstract Escalating conflicts between grassland farming and wintering geese in northern Germany stimulated a long‐term study in order to promote a fair and workable system of compensation of harvest loss. Between 1996 and 2018 standardized experiments were carried out to quantify changes in yield loss and herbage quality. Simultaneously, we weekly monitored the number of geese to relate yield losses to goose numbers and to identify the impact of the different species. Exclosure experiments were established on conventionally managed grasslands. The number of investigated fields differed over the study period (1990s: n = 6, 2000s: n = 14, 2010s: n = 2–18). On each field, we established 12 marked plots (4.5 m2), six with exclosures from early November until the first cut of grass in May and six with access for the geese. In all plots dry biomass and the quality of herbage (contents of energy, crude protein, crude fibre and ash) were determined at first and second harvest. The total goose‐dependent yield losses at first harvest increased from 15% in the year 1996/97 to 50% at the end of the 2010s. The increase corresponds with changes in the maximum numbers and the migratory behaviour of the barnacle goose Branta leucopsis. Yield reductions correlated positively with densities of barnacle geese present in April. In contrast, we found no decline in grassland yields with increasing numbers of greater white‐fronted geese Anser albifrons. In all periods second harvest was not affected. The combined maximum number of both geese which were counted over approximately 23,000 ha of grasslands increased until 2002/03 but levelled off with numbers around 100,000 birds thereafter. While the maximum wintering population of greater white‐fronted geese dropped since 2007/08, the maximum number of barnacle geese increased until mid of 2010s. An increasing proportion of barnacle geese delayed their departure until May. Within each year grazed plots possessed higher energy and crude protein contents than ungrazed controls, suggesting that the geese maximize their potential nutrient intake rate by grazing. Synthesis and applications. The present study reveals a significant increase in goose‐related loss of grassland yields which form the basis for a fair and comprehensible system of compensation payments to affected farmers.

Long-term effects of extensive grazing on pasture productivity

Context In grazed grassland, the per area output of animal-source products usually declines with decreasing stocking rates because of lower herbage utilisation efficiency. Consequently, nutrient export is larger with increased stocking intensity, which should decrease the productivity in the long term. However, little information is available on long-term productivity of extensive grasslands under varied stocking intensities receiving no input. Aims The effect of stocking intensity was investigated in a long-term grazing trial over 16 years of production. We hypothesised that, despite minimal nutrient export under grazing, no reduction in productivity occurs over long-term periods, but expected an interaction between stocking intensity and year. Method The net pasture productivity was determined in terms of animal performance assessed from Fleckvieh cows grazing in a randomised block design with three replicates in three different stocking intensities (moderate, lenient, and very lenient, corresponding to stocking rates of 1.1, 0.7, and 0.5 livestock unit/ha.year respectively), recorded from 2005 to 2020. Metabolisable energy in GJ/ha.year (MEtotal) provided by the pasture and the livestock unit grazing days/ha.year (LUGD, 1LU = 500 kg) were calculated on the basis of liveweight measurements. Key results The interaction of year and treatment significantly affected LUGD (F = 16.85, d.f. = 30, P &lt; 0.0001) and MEtotal (F = 12.81, d.f. = 30, P &lt; 0.0001) and indicated a cyclic trajectory with increases and decreases in performance over the study years. Overall, the moderate stocking intensity led to and maintained significantly higher performance than did very lenient grazing of up to 60% and 55% in LUGD and MEtotal respectively. However, structural equation modelling indicated a negative temporal trend irrespective of stocking intensity. Conclusions On the basis of existing data of herbage quality and botanical composition from the same experiment, this trend was likely to be a result of nutrient redistribution within pastures that probably changed the botanical composition and grass sward productivity in conjunction with drier years towards the end of this study period. Implications This study showed that productivity in low-input grassland under continuous grazing declines over time irrespective of stocking intensity. Productivity decline in all treatments implies tradeoffs for farmers grazing at lower stocking intensities.

Comparison of Some Alfalfa (Medicago sativa L.) Genotypes in terms of Herbage Quality Characters

Comparison of Some Alfalfa (Medicago sativa L.) Genotypes in terms of Herbage Quality Characters

Will the grass be greener on the other side of climate change? (with corrigendum)

Increasing atmospheric [CO2] is stimulating photosynthesis and plant production, increasing the demand for nitrogen relative to soil supply with declining global foliar nitrogen concentrations as a consequence. The effects of such oligotrophication on the forage quality of sweetveld, mixed veld, and sourveld grasslands in South Africa, which support livestock production and native ungulates, are unknown. Soil characteristics and the herbage quality of an abundant grass are described from baseline historical (mid- 1980s) data collected across a sweet-mixed-sour grassland gradient in KwaZulu-Natal. Sourveld occurred on the most acidic, dystrophic soils and exhibited a pronounced decline in leaf nitrogen, digestibility, and other macronutrients during winter, in sharp contrast to sweetveld, on nutrient-rich soils, where forage quality varied little seasonally. In a carbon-enriched, warmer, and most likely drier future climate, we predict that forage quality will not be substantially altered in sweetveld where soil nutrients and temperature are not limiting but that sourveld could become ‘sourer’ because soil nutrients will be inadequate to match higher plant production promoted by elevated [CO2] and warmer and longer growing seasons. Reassessing historical data and seasonal and spatial monitoring of forage quality will enable assessment of past and future impacts of climate change on grassland forage quality. Significance: Grassland forage quality will likely decline with elevated [CO2] and warming, particularly in sourveld. Climate change could deepen and widen the sourveld winter forage bottleneck, necessitating greater supplementary feeding of livestock.