Alfalfa Pasture Research Articles

Innovative Tillage Practices to Establish Productive and Sustainable Forage Production Systems in Degraded Alfalfa Pastures in Semiarid Regions

ABSTRACTTillage management practices play a critical role in maintaining sustainable forage production systems in degraded alfalfa (Medicago sativa L.) pastures. However, climate change leads to the precipitation exhibits greater variability, the impacts of tillage practices on alfalfa productivity and forage quality as well as the relationships between water consumption and soil properties remain poorly understood. The field trial conducted from 2018 to 2020 aimed to investigate the impacts of different tillage treatments (i.e., no tillage [CK], strip subsoiling tillage [ST], strip rotary tillage [RT], and strip rotary tillage after strip subsoiling [SRT]) on soil properties, water use efficiency (WUE), and forage productivity. Compared with CK, tillage practices significantly increased forage biomass and crude protein yield (CPY), particularly in the case of the SRT treatment, in which the increase was 20.8% and 25.3% higher, respectively (p < 0.05). Meanwhile, the net income in the SRT treatment exhibited the greatest value (US $1922.0 ha−1), showing a 17.0% increase compared with that in the CK treatment. The relationship of soil structure and crop water consumption became evident when tillage practices were applied in the degraded alfalfa pasture. The soil bulk density under the ST, RT, and SRT treatments decreased by 6.9%, 5.4%, and 8.6%, whereas the soil porosity increased by 8.6%, 6.7%, and 10.7% in the 0–60 cm soil layer, respectively (p < 0.05). Furthermore, the soil water content at a depth of 0–60 cm increased by 12.1% in the SRT treatment compared with the CK treatment at the harvesting stage, and the SRT treatment obtained the highest WUE of dry matter (16.9 kg ha−1 mm−1) and precipitation use efficiency of dry matter (15.8 kg ha−1 mm−1). In addition, total nitrogen in the ST, RT, and SRT treatments increased significantly by 21.4%, 11.1%, and 27.0%, respectively, and soil organic carbon in the ST, RT, and SRT treatments also increased significantly by 5.5%, 3.3%, and 10.4%, respectively, compared with those in the CK treatment (p < 0.05). Our study has demonstrated that tillage practices can optimize soil structure, improve water utilization, and increase soil fertilizer for enhancing forage productivity. The SRT practice could be a preferable approach for sustainable agricultural production of degraded alfalfa grassland in the semiarid region of China.

How does finishing duration on lucerne pasture influence the muscle and fat spectro-colorimetric properties and dorsal fat firmness in lambs?

There are a number of differences in the meat and carcass quality traits between pasture-raised and concentrate-raised lambs that may further be used to trace back the diet, but the extent to which these differences are modulated by pasture-finishing duration is unknown. In this study, we investigated the changes in longissimus thoracis et lumborum muscle and fat spectrocolorimetric properties, and dorsal fat firmness, in lambs switched from a stall-fed concentrate-based diet to grazing on lucerne for various durations (0, 21, 42, 63 days) pre-slaughter. Stall-fed lambs from the different treatment groups were managed in a single group and lucerne pasture-finished lambs from the different treatment groups also co-grazed in a single group. The level of concentrate fed to stall-fed lambs was adjusted to maintain a similar mean pattern of growth between lucerne pasture-fed and stall-fed lambs. The trial used a total of 141 lambs over two successive years. Dorsal fat was firmer in lambs finished on lucerne pasture, even for the shortest finishing duration (21 days), the difference being of commercial importance. Dorsal fat colour and carotenoid content showed changes at 21 days on lucerne pasture but did not change further for longer lucerne pasture-finishing durations. In contrast, perirenal fat lightness, yellowness, chroma and carotenoid content showed changes at 21 days on lucerne pasture and increased consistently with lucerne pasture-finishing duration. Although these changes in fat spectrocolorimetric properties were not, or barely, visible to the naked eye, they could be of interest for authenticating the duration of lucerne pasture-finishing. Muscle redness increased consistently with the duration of lucerne pasture-finishing, the change becoming significant from 42 days on lucerne pasture and being visible to the naked eye. We observed a consistent decrease of muscle hue angle and perirenal fat redness and a consistent increase in perirenal fat hue angle with lucerne pasture-finishing duration, but these changes only became significant from 63 days on lucerne pasture. The pattern of change in the lamb carcass and meat quality traits measured according to lucerne pasture-finishing duration therefore varied between the tissues and quality traits.

Visible-NIR spectroscopic authentication assay for the classification of lamb meat according to pasture-finishing duration

Spectral analysis of meat combined with chemometric analysis has been identified as a promising tool for authenticating livestock-animal diets. The objectives of this study were (i) to determine whether the visible-NIR spectrum of perirenal adipose tissue (PAT) and caudal adipose tissue (CAT) can reliably discriminate lambs pasture-finished for different durations before slaughter, and (ii) to analyze the kinetics of appearance and stabilization of the visible-NIR spectrum-based pasture signature in PAT and CAT. Four groups of 50–55 lambs were used over three years: lambs finished on lucerne pasture for 0 (L0, concentrate-fed in stall), 21 (L21), 42 (L42) and 63 (L63) days before slaughter. Partial least squares discriminant analysis was applied on PAT or CAT visible-NIR spectra to discriminate the groups. No one adipose tissue reliably discriminated the four groups, with less than 62 % lambs correctly classified. However, visible-NIR spectroscopy was able to discriminate stall-fed (L0) from pasture-finished (L21 + L42 + L63) lambs, with an accuracy of 93.8 % and 87.5 % lambs correctly classified based on PAT and CAT spectra, respectively. The lucerne pasture fingerprint (or signature) on visible-NIR spectrum appeared between 0 and 42 days in more than 95 % of lambs. It stabilized between 42 and 63 days in CAT, but had not stabilized within the range of grazing durations pre-slaughter explored in PAT. Further research into shorter and longer pasture-finishing durations could help determine more precisely the time required for the pasture signature to appear and stabilize in animal tissues.

Effect of irrigation and grazing on the production of an alfalfa pasture (Medicago sativa L.)

La alfalfa es una especie forrajera muy utilizada en Uruguay en ganadería intensiva y lechería. El riego suplementario permite mitigar los efectos negativos del cambio climático, aumentando y estabilizando la productividad de las pasturas. Es necesario evaluar su efecto conjunto con el pastoreo. Se evaluaron dos umbrales de riego, con entrada de animales. Los tratamientos fueron: riego frecuente (30% agotamiento), riego espaciado (65% agotamiento) y secano. El diseño experimental fue de bloques completos al azar, 30 meses de evaluación. La productividad promedio anual de la alfalfa regada fue de 25333 y 23177 kg MS ha-1, primer y segundo año de evaluación, respectivamente. La producción acumulada (30 meses) no mostró diferencia significativa entre los tratamientos regados, pero sí entre regados y secano. En el último verano-otoño, la productividad de todos los tratamientos cae a 8660 kg MS ha-1 (regados) y 1756 kg MS ha-1 (secano). Las productividades estacionales indican la conveniencia de regar la alfalfa en verano, ya que el rendimiento aumentó 43% en el segundo año y 4,3 veces más en el último año. Además, luego de transcurrir la sequía extrema del verano, en el otoño siguiente los regados rindieron 7 veces más que el secano. El manejo con riegos espaciados y láminas de riego que no devuelven el suelo a su capacidad de campo aumenta la efectividad de las precipitaciones, ahorrando agua y energía destinada al riego. La densidad aparente aumentó hacia el final del experimento a consecuencia del pastoreo, sin embargo, no hubo diferencia entre los manejos de riego evaluados.

Аграрное развитие Аргентины во второй половине XIX – начале ХХ вв.

The work is devoted to the final stage in the formation of agrarian regime in Argentina. The foundation for contempo-rary Argentina was built at that time On the Argentina pampas a significant change took place. A land that had produced cat-tle useful only for hides, tallow and salted beef was trans-formed into cultivated fields and pastures where fences closed stock into alfalfa pastures. The rise of the farming and sheep ranching accompanied this shift in the cattle economy. Frigorificos – plants for production of chilled beef made it possible to be sold in markets of Great Britain. Argentina be-came one of the world’s leading exporters of wheat, corn, beef mutton and wool. It indicates that behind this economic accomplishment lies land structure – the predominance of large ownership – latifundia. Argentina had no homestead act or other long-seal land distribution plan that wood root immi-grants to the nation by granting them ownership of the soil. The Argentina landed elites owned most of the good land with the result that immigrants became tenants on short term leases. The farming developed primary as servant to the predom-inant sheep and cattle interests. The result was a pampa without settler filled with migrant tenant farmers a land exploited but not possessed. The predominance of latifundia and the land tenant system retarded the intensification of agrarian sector: Argentina failed to build a modern agrarian economy.

The prolonged effect of film mulch and P application on lucerne forage yield in a semiarid environment.

Limited water and soil phosphorus (P) availability often hampers lucerne productivity in semiarid regions. Plastic film mulch and P application typically enhance young lucerne (2-3 years) productivity by increasing soil water use and P availability. However, the prolonged impact of film mulch and P application on lucerne productivity as the stand ages remains unclear. This study conducted a 9-year field experiment on the semiarid Loess Plateau to investigate how film mulch and P application affect lucerne forage yield, soil water content, and soil fertility. The field experiment used a split-plot design with randomized blocks, in which the whole plots were with (M1) and without plastic film mulch (M0), and the split plots were four P rates (0 (P0), 9.7 (P1), 19.2 (P2), and 28.8 (P3) kg P ha-1). The M1 treatment produced significantly higher lucerne forage yields than the M0 treatment during the first five years, but the yield-increasing effect of film mulch gradually diminished over time, with no effect in Years 6-8, and lower yields than the M0 treatment in Year 9. Phosphorus fertilization significantly increased forage yield after Year 3 in the M0 treatment, but only in Years 3-5 in the M1 treatment. In Years 2-5, film mulch significantly increased soil organic carbon, total nitrogen (N), inorganic N, and microbial biomass carbon in P0, P1, and P2 but not in P3. However, in Years 7-9, film mulch significantly decreased soil available potassium (K), organic carbon mineralization, lucerne density, and shoot K concentration, but did not reduce soil N and P availability at any level P of application. Moreover, plastic film mulch significantly increased the soil water content at 0-300 cm deep from Year 7 onwards. In conclusion, film mulch ceased to enhance lucerne production beyond year 6, which could not be attributed to soil water content, N or P availability but was partially associated with reduced soil K availability. Consequently, future research should focus on soil K availability, and K addition should be considered after five years in lucerne pastures mulched with plastic film in semiarid areas.

An insight into sainfoin (Onobrychis viciifolia Scop.) breeding: Challenges and achievements

AbstractOver the last decade, there has been a renewed interest in sainfoin (Onobrychis viciifolia Scop.), particularly among western Canadian forage and beef‐cattle producers. A major trigger has been the availability of new sainfoin cultivars with improved compatibility with alfalfa (Medicago sativa). These new cultivars in binary mixture with alfalfa significantly reduced the incidence of alfalfa pasture bloat in grazing animals, potentially saving an estimated CAD 300–500 million worldwide, largely by eliminating direct animal losses and expenses associated with prevention and treatment. Although the development of new sainfoin cultivars was a significant breakthrough, this alone did not ensure its adoption by producers in western Canada. Indeed, concerns and questions endured, including whether sainfoin cultivars could in fact grow together with alfalfa and persist as a perennial crop, whether including sainfoin in alfalfa stands would make the pasture bloat safe, whether the biomass yield of sainfoin was comparable to that of alfalfa for a profitable return, and whether livestock would graze sainfoin to the same extent as alfalfa. In this review study, we provide an overview of sainfoin breeding research and discuss how new sainfoin cultivars (AAC‐Mountainview and AAC‐Glenview) were developed in Canada for binary mixtures with alfalfa. Additionally, we highlight current progress in sainfoin breeding efforts and the prospect of this species as a livestock feed for a sustainable agriculture system.

Including 8 hours of access to alfalfa in 1 or 2 grazing sessions in dairy cows fed a partial mixed ration: Effects on intake, behavior, digestion, and milk production and composition

The aim of this study was to evaluate the inclusion of alfalfa grazing during 8 h continuous or partitioned in 2 separated sessions of 4 h after each milking, on nutrient intake, digestibility, ruminal fermentation, feeding behavior, milk production, milk composition, and milk fatty acid profile, in late-lactation cows fed a partial mixed ration (PMR). Twelve dairy cows (193 ± 83 d in milk, 584 ± 71 kg of body weight) were housed in individual outdoor pens and assigned to treatments according to a 3 × 3 Latin square design replicated 4 times. The treatments were as follows: (1) control (T0), cows were fed a total mixed ration (TMR) provided ad libitum 20.0% crude protein (CP), 32.2% neutral detergent fiber (NDF); (2) fed a diet combining a PMR which had the same ingredient composition as the TMR (60% of ad libitum intake) + 1 session of 8 h of pasture (T8), continuous grazing alfalfa (Medicago sativa; 20.6% CP, 35.8% NDF) after the p.m. milking; and (3) PMR (60% of ad libitum intake) + 2 daily sessions of 4 h of access to pasture after each milking (T4+4). The experiment lasted 57 d and was divided into 3 periods of 19 d each. The first 12 d of each period was used for diet adaptation, and the last 7 d was used for data collection. No differences among treatments were observed for any of the productive variables, feeding efficiency, or purine derivatives excretion. Cows in T0 had greater intake and apparent digestibility of dry matter, organic matter, and nonfibrous carbohydrates compared with T4+4 and T8. Compared with T0, alfalfa grazing increased the concentration of C18:1 trans-11 and decreased those of C16:0 and C17:0 in milk fat. Cows in T4+4 consumed 1.1 more kg DM/d of alfalfa and N provided by alfalfa in the diet was 3 percentage points higher compared with T8 cows (266 vs. 229 g/d, respectively). In addition, T4+4 cows had a greater daily range of ruminal pH than T8 (0.73 vs. 0.93), and the highest concentrations of NH3-N were recorded during the a.m. grazing session while in T8 cows it occurred during the night. In conclusion, including 8 h of alfalfa grazing in T8 and T4+4 treatments allowed the substitution between 35.8 and 38.7% of the total dry matter intake (DMI) of a PMR (with a similar CP concentration to alfalfa) for pasture, maintaining milk solids production and increasing the C18:1 trans-11 of milk fat compared with a TMR in mid late-lactation cows. In an herbage plus PMR diet, splitting the 1 continuous grazing session of 8 h into 2 sessions of 4 h increased the proportion of energy and N provided by alfalfa pasture and reduced PMR intake, without modifying the total nutrient intake or productive performance of cows.

Responses of Deep Soil Carbon and Nitrogen Contents to Long-Term Retention of Alfalfa Pasture on Infertile Loess: A Synthesis Study

Incorporating perennial pastures into annual crop systems is an efficient means of improving soil carbon (C) sequestration and reducing the application of nitrogen (N) fertilizer on farmlands. How the soil C and N at different soil depths respond to the length of pasture duration and rainfall conditions is still being determined. In this study, we conducted a meta-analysis of data from 63 published studies to investigate the impacts of the alfalfa pasture on the incorporation of soil organic carbon (SOC), total nitrogen (STN), and available nitrogen (SAN) contents in the 0–300 cm soil profile of the Loess Plateau. An annual crop field was taken as a reference. The results showed that the average SOC content at soil depths of 0–100 and 100–200 cm in the alfalfa pasture increased by 17% and 8% (p < 0.001) compared to the crop field, respectively, while that at 200–300 cm decreased (p > 0.05). The SOC content increased with pasture age; it was the highest when the alfalfa had been planted for 5–9 years and decreased thereafter. The STN content at soil depths of 0–100 and 100–200 cm increased by 19% and 14% (p < 0.001), respectively; the content at depths of 200–300 cm only increased slightly (p > 0.05). It also increased the most when the alfalfa was 5–9 years old. The increments in the SAN content at the 0–100 and 100–200 cm soil depths were higher than those of the STN, with values of 29% and 18%, respectively, while those at depths of 200–300 cm also changed insignificantly (p > 0.05). The SAN content continuously increased with the age of the alfalfa, and the average increment in the 0–300 cm profile was as high as 21% when the alfalfa was ≥10 years old. The SOC and STN content increased the most under moderate rainfall conditions (350–500 mm), while the SAN content maintained the highest increment under high rainfall (500–650 mm) conditions. Therefore, ley farming with the alfalfa pasture contributed substantially to the soil C and N at depths of 200 cm in deep loess. Alfalfa should be removed in its middle ages to increase C sequestration while utilizing soil N efficiently.

Change in fat skatole and indole content in lambs switched from a concentrate-based diet indoors to alfalfa grazing for various durations before slaughter

Meat from lambs fattened on alfalfa is at risk of excessive pastoral flavours due to high levels of in-fat volatile indolic compounds (especially, skatole). Skatole has also been identified as a potential marker of interest for authenticating pasture-fed lamb meat. Here, we investigated the change in skatole and indole concentrations in kidney fat from lambs switched from an indoor-fed concentrate based diet to outdoor alfalfa grazing for various durations (0, 21, 42, 63 days) before slaughter. The study used a total of 219 lambs over 3 consecutive years. Kidney-fat skatole and indole concentrations increased from as early as 21 days on alfalfa, and then reached a plateau. Similarly, the proportion of lambs that had a kidney fat-skatole concentration above 0.15 μg/g liquid fat, a value that has been established as a sensory rejection threshold for pork, increased significantly from as early as 21 days on alfalfa and then reached a plateau. This value was reached or exceeded in a significant proportion of lambs fattened on alfalfa pastures (45.1%). However, skatole was not detected in kidney fat from 20 out of 164 alfalfa-fattened lambs (i.e., 12.2%) but was detected in 15 out of 55 concentrate-fed lambs (i.e., 27.3%). We thus conclude that while skatole content in kidney fat can inform on dietary changes made shortly before slaughter, it does not have the discrimination power needed to reliably authenticate pasture-fed lamb meat, let alone duration of finishing on pasture.

Assessing trade-offs among productive, economic, and environmental indicators of forage systems in southern Tibetan crop-livestock integration

Fostering crop-livestock integration via crop-forage rotation provides opportunities to cope with land degradation, feed deficit, and agropastoral sustainability. Farmers' preferences for forage options are influenced by economic benefit, environmental preference, and productive performance. However, there is little information available on evaluating multiple trade-offs of forage systems for the design of crop-forage rotations. Here, we performed a comprehensive evaluation to compare the economic, environmental, and productive indicators of five typical forage systems in terms of habitat conditions, soil ecosystem services, economic profit, and forage yield and nutritive value on the southern Tibetan Plateau. Alfalfa pasture and silage corn were mostly cultivated in lower altitudes, with more abundant precipitation, and higher growing degree days. Soil carbon and nitrogen accumulation were significantly higher in perennial alfalfa than in the other forage systems. The relative feed value of alfalfa pasture was also evidently greater than the other forage systems, whereas the yield of silage corn was among the highest. Alfalfa pasture presented superior economic benefits compared to the others. But the alfalfa pasture over six years showed a significant decrease in soil carbon and nitrogen storage, net present value, and yield. Forage systems generally have more soil carbon accumulation, but only forage legumes are more likely to positively affect soil nitrogen retention compared to cereal croplands. The trade-offs among economic, environmental, and productive indicators demonstrated that annual forage systems (silage corn, forage oat, and ryegrass) met productive target rather than environmental and economic objectives, while perennial alfalfa showed synergies among the three goals. These findings indicate that integrating crop-forage rotation, particularly introducing legume forages into farming systems is an adaptive option for crop-livestock integration on the southern Tibetan Plateau. Given the large topographic variation, suitable crop-forage systems should be designed for the heterogeneous Yarlung Zangbo River valleys. Among them, alfalfa-silage corn intercropping is recommended as a promising system to meet both productivity and profitability.

Priorities for the development of alfalfa pasture in northern China.

Alfalfa (Medicago sativa L.) is acclaimed as "Queen of forages" because of its great yield and high feeding value. China is the second biggest country in acreage of alfalfa cultivation, but the cultivation regions of alfalfa are distinguished by adverse climatic and edaphic conditions in northern China. Moreover, the lack of elite alfalfa varieties with great adaptation and poor field management are vital factors limiting development of alfalfa pasture in China. In addition, nutritional quality of alfalfa in China is also poor compared to that in countries of developed animal husbandry industrial. Here, we propose several priorities in terms of a comprehensive system of alfalfa breeding, field management, harvest and processing with Chinese characteristics, based on the theories and methodologies of breeding science, agronomy, plant physiology and agricultural machinery. Implementation of these priorities will greatly contribute to the sustainable development of the alfalfa pasture in China.

Deep soil water depletion and soil organic carbon and total nitrogen accumulation in a long‐term alfalfa pasture

AbstractDeep soil resources are essential for improving the production and ecological functions of dryland ecosystems. Relationships between deep soil water depletion and carbon and nitrogen accumulation in long‐term dryland pastures were not well quantified and understood. This study aimed to quantify the changes in deep soil water, soil organic carbon (SOC), and total nitrogen (TN) in alfalfa pasture and identify their relationships with root density. We conducted a field experiment in the south Loess Plateau in 2020 and 2021. Soil water, SOC, and TN contents and alfalfa root length density to 1000‐cm‐depth were measured in alfalfa pastures and annual crop reference fields. Soil water depletion by alfalfa mainly occurred in the first 6 years with a depletion rate of 41.6, 49.1, and 62.1 mm yr−1 in the shallow (0–200 cm), middle (200–500 cm) and deep (500–1000 cm) soil layers, respectively. Total depletion after 6 and 19 years were 916.8 and 1049.4 mm, respectively. SOC and TN storages in the shallow and middle layers continuously increased and peaked at 19 years after planting, and those in the deep soil increased quickly in the early ages but showed few changes in the following years. Final SOC and TN storages in the 0–1000 cm profile in alfalfa pasture reached 61.1 and 5.4 kg m−2, respectively, 13.7% and 20.4% higher than the reference field. Soil in 200–1000 cm contributed to 60.7% and 47.8% of the total SOC and TN storage increments, respectively. The deep rooting system of alfalfa derived soil water depletion and SOC and TN increments, as indicated by the significant relationships between fine root length density and the changes in soil water, SOC and TN storages. Therefore, the deep soil contributed substantially to the carbon and nitrogen sequestration in alfalfa early ages but the contribution was limited by water shortage in the middle and late ages. We suggest stopping alfalfa early (≤6 years) to increase water sustainability and maintain carbon and nitrogen sequestration efficiencies in the alfalfa pasture and crop rotation system on Loess Plateau.

Simulating the population dynamics of barley grass (Hordeum spp.) and impacts of weed management strategies in a southern Australian lucerne (Medicago sativa) pasture

Context Barley grass (Hordeum spp. L.) is an annual, invasive grass weed of southern Australian crops and pastures, frequently associated with weight loss and carcass damage in sheep due to its sharp seeds. Knowledge gaps exist regarding optimal density thresholds for effective control to reduce impacts on animal production. The value of integrated weed management (IWM) over individual control options for reducing barley grass populations in pasture is also unknown. Aims We aimed to develop a model for simulating the population dynamics of barley grass within lucerne (Medicago sativa L.) pastures of southern Australia and to test the hypothesis that combining herbicides with mowing will be more effective for removing barley grass seedbanks over time than individual control measures. Methods The model was developed within Microsoft Excel and adapted from other annual grass models. The model takes a Monte Carlo approach to simulate control impacts on weed seedbanks over 10 years using five weed-control density thresholds. It was parameterised using data from recent experiments and available literature. Key results The most effective long-term control strategy for barley grass occurred with a density threshold of 5 seedlings m−2 by combining early and late herbicide applications, and by combining early and late herbicides with mowing, reducing the seedbank by 86% and 89%, respectively. Conclusions Simulation results showed that IWM programs were more effective than individual control options in reducing the barley grass seedbanks over 10 years, particularly at low weed densities (≤50 seedlings m−2). Implications Incorporation of this model into a bioeconomic grazing systems model will be valuable for determining the economic impacts and optimal weed-control strategies for minimising the effects of barley grass seed contamination in lamb production systems.

Sown alfalfa pasture decreases grazing intensity while increasing soil carbon: Experimental observations and DNDC model predictions.

Grasslands are the most important land use in China and have experienced extensive degradation in the past few decades due to overgrazing. However, regionally viable solutions to grazing intensity alleviation remained elusive to date. Here, we evaluated the grazing intensity effects of sown alfalfa pastures in northern China using an experiment-modeling combined approach that involved six sites in field experiments and five provinces in DNDC modeling of sown alfalfa pasture's forage production and carbon sequestration potentials in marginal lands. Our results showed that the sown alfalfa pasture's dry-matter yield varied between 4.5 and 9.0 Mg ha-1 under rainfed and irrigated conditions, respectively, from 2025 to 2035. If half of the available marginal lands were mobilized for alfalfa forage production, these yield levels meant that livestock grazing intensity on natural grasslands may drop 8-13% under rainfed and 20-33% under irrigated conditions. Our results also showed that marginal land's soil organic carbon contents were systematically higher under sown alfalfa pasture than under fallow management by a big margin of 8.5 and 9.9 g kg-1 (i.e., +79 and +95%), under rainfed and irrigated conditions, respectively, during 2025-2035. Overall, these results demonstrated that sown alfalfa pasture on marginal lands represents an effective grassland conservation pathway over the short- to medium-term time horizon based on current technologies.

Is a short concentrate-finishing period in lambs raised on alfalfa pasture effective at reducing fat indoles contents and lightening meat colour?

Pasture-feeding in lambs has been associated with dark-coloured meat and high meat contents of volatile indoles (skatole and indole), which may be responsible for sensory defects. The risk of off-flavours is even higher when lambs graze alfalfa, because it is particularly rich in rapidly degradable proteins. Here, we investigated whether a short concentrate stall-finishing period in lambs that previously grazed alfalfa influences meat sensory quality traits. We compared three feeding treatments, using three groups of 10 male Romane lambs: grazing alfalfa (A), stall-feeding with concentrate and straw (S), and stall-finishing with concentrate and straw for 21 days after previously grazing alfalfa (AS). During stall-feeding, the concentrate was given at a level adjusted to achieve a similar growth pattern in all treatment groups, and the length of the trough was sufficient for all lambs to have access to the feeds at the same time. Lamb live weight and age at slaughter, and carcass conformation and fatness were similar for all treatment groups. Perirenal fat skatole content was lower in AS and S lambs than in A lambs (P < 0.001 and P < 0.05, respectively), and not significantly different between AS and S lambs. Perirenal fat indole and dorsal fat skatole concentrations were lower in AS lambs than in A lambs (P < 0.05 and P < 0.005, respectively), the other pairwise comparisons being not significant. There was no treatment effect on dorsal fat indole content. Longissimus et lumborum muscle colour coordinates differed between pasture-fed and stall-fed lambs, with a lower lightness (P < 0.005) and greater redness and hue angle (P < 0.001 and P < 0.01, respectively) in pasture-fed lambs, but muscle colour coordinates did not differ between A and AS lambs. A 21-d concentrate-based stall-finishing period in lambs previously raised on alfalfa pasture therefore markedly reduced fat indoles concentrations compared to lambs grazed on alfalfa until slaughter but did not change meat colour.

FARM DAIRY EFFLUENT APPLICATION ON AN ARGIUDOLL CULTIVATED WITH ALFALFA (Medicago sativa L.): BIOMASS PRODUCTION AND PERSISTENCE

The intensification of dairy production systems has resulted in a higher generation of waste. The aim of this study was to evaluate the impact of different doses of farm dairy effluent (FDE) applied to the soil on aerial biomass production, persistence and chemical composition of alfalfa pastures, in Santa Fe province, Argentina. The study was conducted in four randomized complete blocks with four treatments (FDE doses): 0 m3 ha-1 (T0: without FDE), 82 m3 ha-1 (T1: low rate), 151 m3 ha-1 (T2: medium rate) and 282 m3 ha-1 (T3: high rate). The soil application of FDE increased the total aerial biomass produced (ABP) but reduced the persistence of plants. Total nitrogen (Nt) of alfalfa was significantly higher, but phosphorus (P) concentrations did not vary after the application of FDE to the soil . Ca and Mg concentrations in plants were lower in T3 compared to T0, which can be explained by the imbalance produced in the soil after FDE was applied, presenting high levels of Na, K and NH4-N but low levels of Ca and Mg. Soil application of FDE on alfalfa pastures must be carefully planned in terms of composition and amount to be applied in order to increase biomass production, prevent the decrease in persistence, and control changes in the mineral composition of plants.

Evaluating nondestructive forage sampling techniques in alfalfa–bermudagrass mixtures in the southeastern United States

AbstractThe increased use of legume–grass mixtures in grazing systems has resulted in the need for more accurate forage estimation techniques for these diverse mixtures. In mixed stands, variations in species composition and canopy density make the estimation of herbage mass (HM) challenging. Three nondestructive sampling techniques [a rising plate meter (RPM), a pasture ruler, and digital image analysis] were compared with traditional botanical hand separation to determine their effectiveness in predicting HM in bermudagrass [Cynodon dactylon (L.) Pers.] and alfalfa (Medicago sativa L.) pastures when harvested to a 1‐ or 4‐inch stubble height. All models calibrated to forages harvested to 1 inch failed to meet the formal assumptions of the F‐test. The height and RPM were moderately successful at predicting HM when calibrated to samples harvested to 4 inches. However, the models were unable to predict HM above 4,000 lb acre−1 in their current form. Future research in alfalfa–bermudagrass mixtures should focus on isolating how HM changes within the canopy and increase the sample area used to collect the calibration data.

Monitoring Rainfed Alfalfa Growth in Semiarid Agrosystems Using Sentinel-2 Imagery

The aim of this study was to assess the utility of Sentinel-2 images in the monitoring of the fractional vegetation cover (FVC) of rainfed alfalfa in semiarid areas such as that of Bardenas Reales in Spain. FVC was sampled in situ using 1 m2 surfaces at 172 points inside 18 alfalfa fields from late spring to early summer in 2017 and 2018. Different vegetation indices derived from a series of Sentinel-2 images were calculated and were then correlated with the FVC measurements at the pixel and parcel levels using different types of equations. The results indicate that the normalized difference vegetation index (NDVI) and FVC were highly correlated at the parcel level (R2 = 0.712), whereas the correlation at the pixel level remained moderate across each of the years studied. Based on the findings, another 29 alfalfa plots (28 rainfed; 1 irrigated) were remotely monitored operationally for 3 years (2017–2019), revealing that location and weather conditions were strong determinants of alfalfa growth in Bardenas Reales. The results of this study indicate that Sentinel-2 imagery is a suitable tool for monitoring rainfed alfalfa pastures in semiarid areas, thus increasing the potential success of pasture management.

Performance, carcass and meat traits of beef steers finished on small-grain winter annuals in winter or on alfalfa pasture in summer

Performance and carcass traits of beef steers finished on small-grain winter annual pastures (SGWA) or alfalfa were compared. Treatments consisted of pure stands of cereal rye, triticale, wheat or alfalfa (Rye, Trit, Wht, and Alf, respectively). The 3 SGWA species were grazed during winter and early spring. Alfalfa was grazed during spring and summer. Three pasture replicates were assigned to each treatment with 10 animals each. A minimum of 7-mm subcutaneous rib fat thickness (determined by ultrasound) was defined as slaughter endpoint. After a 98-d finishing period all animals from Rye, Trit and Wht reached the target, and were ready for harvest. Alfalfa animals were slaughtered after 120 days. After slaughter, carcasses were individually graded and weighed to determine hot carcass weight (HCW) and hot carcass yield (HCY) was calculated. Seventy-two h post-slaughter, a section of steaks including the longissimus thoracis muscle (LT) was removed from the left side of each carcass for analysis including rib fat thickness (RFT), LT area (LTA), Warner-Bratzler-shear force (WBsf), drip-loss, cooking loss, instrumental color, muscle pH, sensory analysis, intramuscular fat content and lipid profile. Proximate composition, and lipid profiles of pastures offered were also determined. Alf animals had lower (P < 0.01) ADG than SGWA animals. Alfalfa animals took 22 days longer to reach the slaughter point. However, no pasture effects were detected (P ≥ 0.14) for HCY, LTA, RFT, WBsf, pH, muscle a* and b*, and subcutaneous fat L*, a* and b* color parameters. Muscle L* was greater (P < 0.05) and drip and cooking loss were lower (P ≤ 0.05) for Alf. Sensory panel scored Alf beef of greater (P < 0.01) juiciness, tenderness and beef-flavor. Rye beef was attributed highest off-flavor score. Alfalfa and Wht beef showed similar (P = 0.40) FA content, higher (P ≤ 0.02) than Rye and Trit beef. Rye beef had the lowest (P ≤ 0.02) FA content. Within the FA fraction, Alf had lower (P ≤ 0.02) proportion of SFA, greater t-MUFA content, greater (P ≤ 0.01) total n-3 concentration and the lowest n-6/n-3 ratio (P ≤ 0.01). Alfalfa beef resulted in greater (P ≤ 0.01) total CLA concentration. Although lipid profiles of forages related to observations in lipid profiles of beef, differences in drip and cooking loss and sensory attributes of beef that favored of alfalfa finishing were not explained in animal performance and fatness.