Management-intensive Grazing Research Articles

Determination of gas flux of growing steers under intensive grazing conditions.

Ruminants produce one-third of the anthropogenic methane (CH 4 ) emissions worldwide, and 47% of the CH4 emissions result from ruminants under grazing conditions. However, there is limited information regarding the appropriate number of visits to accurately determine enteric CH4 emissions using the automated head-chamber system (AHCS) from growing beef cattle under intensive grazing conditions. Data from one experiment were analyzed to determine the number of visits to assess gas flux (CH4, carbon dioxide [CO 2 ], and oxygen [O 2 ]) from Angus-crossbreed steers grazing in a pivot-irrigated improved pasture. A total of 110 steers (324 ± 37.3 kg initial body weight) were selected and divided into two blocks. Steers were under intensive grazing management for 84 d. Depending on forage availability, steers were rotated at 2- to 4-d intervals. Pastures were predominately composed of cool-season forages. Two different databases using the same animals (n = 16) were defined to calculate the gas flux using the first 100 visits to an AHCS with 2 or more or 3 or more minutes of visitation length. The mean gas flux was estimated as the average for increasing (forward) or decreasing (reverse) the gas flux of 5-visit intervals starting with the first or the last 5 visits and increasing or decreasing until the full 100-visit dataset was utilized, respectively. Spearman and Pearson correlations were computed between the maximum visits and each shortened visit interval. Concurrently, the residual variance and the residual variance change were determined for each interval by fitting a mixed model. The minimum number of visits was defined when correlations with the total visits were greater than 0.95, and the residual variance was stabilized. The results indicated that the minimum number of visits needed to determine CH4 production varied between 45 and 70, while CO2 production and O2 consumption varied between 45 and 50 according to the visitation length. Additionally, steers that visited the AHCS for 2 or more minutes in visit duration required a greater number of visits than those that visited for 3 or more minutes. Thus, based on the average daily visitation in this experiment (1.4 visit/d), the assessment of CH4 emissions requires 32 d, while CO2 production and O2 consumption require between 32 and 36 d using 3 or more minutes of visit length from growing steers under intensive grazing conditions.

Tracking Soil Health Changes in a Management-Intensive Grazing Agroecosystem

Management-intensive Grazing (MiG) has been proposed to sustainably intensify agroecosystems through careful management of livestock rotations on pastureland. However, there is little research on the soil health impacts of transitioning from irrigated cropland to irrigated MiG pasture with continuous livestock rotation. We analyzed ten soil health indicators using the Soil Management Assessment Framework (SMAF) to identify changes in nutrient status and soil physical, biological, and chemical health five to six years after converting irrigated cropland to irrigated pastureland under MiG. Significant improvements in biological soil health indicators and significant degradation in bulk density, a physical soil health indicator, were observed. Removal of tillage and increased organic matter inputs may have led to increases in β-glucosidase, microbial biomass carbon, and potentially mineralizable nitrogen, all of which are biological indicators of soil health. Conversely, trampling by grazing cattle has led to increased bulk density and, thus, a reduction in soil physical health. Nutrient status was relatively stable, with combined manure and fertilizer inputs leading to stabilized plant-available phosphorous (P) and increased potassium (K) soil concentrations. Although mixed effects on soil health were present, overall soil health did increase, and the MiG system appeared to have greater overall soil health as compared to results generated four to five years earlier. When utilizing MiG in irrigated pastures, balancing the deleterious effects of soil compaction with grazing needs to be considered to maintain long-term soil health.

Grazing and fertilizer, compost or manure application effects on a meadow bromegrass pasture on a thick black chernozem I. Productivity and sustainability

Short duration, intensive grazing management with high stocking rates may result in sufficient turn-over of nitrogen (N) to compensate for production-limiting soil-N deficiencies for grass pasture. In central Alberta a 0.5 ha block was seeded to “Fleet” meadow bromegrass ( Bromus riparius Rehmann) in August 2002. Within this block, six fenced (9 m × 30 m) treatments were established in three replicates. They were (1) ungrazed—clip removal, (2) grazed—alone, (3) grazed—fertilizer, (4) grazed—fertilizer-compost, (5) grazed—hog manure, and (6) grazed—alfalfa ( Medicago sativa L.) grass. Measurements were conducted over a 4-year period between 2003 and 2006 and grazing occurred at identical times as vegetative mass permitted. Biomass was harvested before and after grazing for calculation of dry matter (DM) yield and biomass consumed. Sub-samples were used for determination of N concentration and in vitro digestibility. Mean herbage N-yield for grazed treatments was 131% of ungrazed and greatest for grazed-fertilizer and grazed-fertilizer plus compost. Grazed paddocks with no added N produced similar DM yield to those with added N. Estimated nitrogen fixation contributed an annual average of 82 kg ha−1 to herbage-N yield from the alfalfa-grass paddocks. Barley ( Hordeum vulgare L.) silage grown after termination of the grazed pastures produced 72% more herbage DM from grazed paddocks than ungrazed, but no significant ( P < 0.05) differences occurred among amendments.

114 Evaluation of Assertions from Educational, Outreach and Engagement Programs in Pasture-Based Livestock Systems

Abstract Assertions about grazing management and grazing systems should be evaluated based on the scientific literature. Prior assumptions can limit our ability to achieve constructive dialogue regarding the merits of various stocking methods. These include the assumption that rotational stocking is inherently superior to continuous stocking, regardless of the nature of the overall grazing system, and the presumption that continuous stocking implies overgrazing. We revisited assertions about grazing management in general, but more specifically the choice of the stocking method, and considered their merit in the context of evidence from the literature, including a chapter titled Prescribed Grazing on Pasturelands from a National Resource Conservation Service (NRCS) literature synthesis published in 2012. We framed those assertions in the form of questions. The questions were: a) Does choice of rotational stocking ensure well-managed pastures?, b) Does rotational stocking result in greater accumulation of soil carbon than continuous stocking?, c) Does rotational stocking increase pasture productivity and optimal stocking rate compared with continuous stocking?, d) Does forage nutritive value and individual animal performance increase in rotational versus continuous stocking?, and e) Do pastures “look better” in rotational versus continuous stocking?. The objectives were to consider whether these often-stated assertions about grazing management were supported, refuted, or simply not adequately assessed by the body of scientific evidence. It is important to recognize that choice of stocking method is only one element of grazing management and grazing management is only one element of a grazing system. Thus, stocking method is “one piece of a very large pie”. Additionally, stocking rate (grazing intensity) is a separate and independent grazing management choice from stocking method, such that both rotationally and continuously stocked pastures can be understocked, overstocked, or optimally stocked. It is unfortunate that choice of stocking method dominates discussions of improving grazing management to the expense of other issues, when in fact intensity of grazing has been shown conclusively to be the most important determinant of a wide array of soil, plant, animal, and ecosystem responses. We have observed that terminology such us regenerative grazing, holistic planned grazing, adaptative multipaddock grazing, management intensive grazing, high intensity low frequency grazing, and others, arise frequently and can dominate discussions in the realm of education, outreach and engagement programs in pasture-based livestock systems. These words/themes lack clear definition, and this lack of specificity may promote misconceptions, thus hindering the opportunity for critical thinking and ultimately the advancement and improvement of grazing systems. Educational efforts in pasture management should strive to remain relevant by focusing on experimental evidence. Local (i.e., state or county level) outreach and engagement programs are challenged with providing timely and specific information with implementable guidelines based on frequent observations at the landscape and farm levels.

The long-term effects of intensive grazing and silvopastoral systems on soil physicochemical properties, enzymatic activity, and microbial biomass

Brazil is the largest exporter and the second-largest beef producer in the world. The country's biggest challenge has been to increase the production capacity of soils in an environmentally sustainable way. In this context, agricultural practices that preserve the environment have demonstrated high productivity and sustainability by emphasizing intensive grazing management and silvopastoral systems. In this study, the effects of the conversion of a native forest (FO) into different pasture-based cattle production systems were assessed in long-term field experiments using microbiological and physicochemical measurements. Five pasture systems were evaluated: i) irrigated high stocking rate pasture (IHS); ii) rainfed high stocking rate pasture (RHS); iii) rainfed moderate stocking rate pasture (RMS); iv) silvopastoral system with moderate stocking rate (SPS); and v) degraded pasture (DP), the latter used as a reference for conventional pasture management, extensively used by farmers. Soil samples (0–10 cm) were analyzed for bulk density (BD), total carbon content (TC), soil organic matter humification index (HLIFS), activities of soil enzymes β-glucosidase (BG) and arylsulfatase (ARYL), microbial biomass carbon (MBC), and basal respiration (BR). The results showed that all managed pastures presented higher soil carbon content than DP (16.2 ± 1.7 g kg−1), especially the RMS system, which presented the highest carbon content (32.9 ± 0.9 g kg−1). Activities of BG and ARYL were more sensitive to detecting management changes than MBC and BR. Increased activities of BG and ARYL were observed in the RMS system, possibly due to the higher amount of biomass input, while this effect was less expressive in the other management systems. The results indicated that soil enzymatic activities are sensitive to land use and management and could be used as soil quality indicators in pasture-based beef cattle production for different systems in tropical soils.

Vegetation and Animal Performance Responses to Stocking Density Grazing Systems in Nebraska Sandhills Meadows

Management-intensive grazing, which is proposed to increase forage and animal productivity and maintain soil integrity and biodiversity, is seen as an alternative to meet 21st century agricultural and environmental challenges. The purpose of this study was to test the hypothesis that high levels of trampling of standing vegetation associated with mob grazing (a.k.a., ultrahigh stocking density) leads to increased plant diversity and productivity. A long-term experiment was established on a subirrigated meadow in the Nebraska Sandhills as a complete block design comparing three grazing treatments applied annually during the growing season for 8 consecutive yr (2010−2017): 120-pasture rotation with one grazing cycle (mob; 225 000 kg live weight ha−1), four-pasture rotation with one grazing cycle (4PR1; 7 000 kg live weight ha−1), and four-pasture rotation with two grazing cycles (4PR2; 5 000 kg live weight ha−1). All treatments were set at a moderate stocking rate (7.4 animal unit months ha−1) using yearling steers. Percentage trampling, plant production, species composition, and steer weight gain were estimated annually. We applied linear mixed-effect models to account for year and treatment effect on the response variables. Percentage trampling on mob pastures ranged from 40% to 55% over the 8 yr of the study, nearly double that of the 4PR1 and 4PR2 pastures. We observed that mob grazing had no overall effect on plant species composition, aboveground production, and root growth relative to low stocking densities. Average daily gain of steers in the mob pastures was less than gain of steers in 4PR2 pastures in all years, with intermediate weight gains for the 4PR1 steers. Overall, stocking density did not appear to be a driver of plant composition and productivity in rotationally grazed pastures on subirrigated meadows in the Nebraska Sandhills.

Management-intensive grazing impacts on total Escherichia coli, E. coli O157:H7, and antibiotic resistance genes in a riparian stream

The impacts of management-intensive grazing (MIG) of cattle on concentrations of total Escherichia coli, total suspended solids (TSS), and nitrate-nitrite nitrogen (NO3 + NO2-N), and occurrence of E. coli O157:H7 and selected antibiotic resistance genes (ARGs) in stream water and/or sediments were evaluated. Cattle were grazed for two-week periods in May in each of three years. Overall, grazing increased total E. coli in downstream water by 0.89 log10 MPN/100 mL (p < 0.0001), and downstream total E. coli concentrations were higher than upstream over all sampling intervals. Downstream TSS levels also increased (p ≤ 0.0294) during grazing. In contrast, there was a main effect of treatment for downstream NO3 + NO2-N to be lower than upstream (3.59 versus 3.70 mg/L; p = 0.0323). Overwintering mallard ducks increased total E. coli and TSS concentrations in January and February (p < 0.05). For precipitation events during the 24 h before sampling, each increase of 1.00 cm of rainfall increased total E. coli by 0.49 log10 MPN/100 mL (p = 0.0005). In contrast, there was no association of previous 24 h precipitation volume on TSS (p = 0.1540), and there was a negative linear effect on NO3 + NO2-N (p = 0.0002). E. coli O157:H7 prevalence was low, but the pathogen was detected downstream up to 2½ months after grazing. Examination of ARGs sul1, ermB, blactx-m-32, and intI1 identified the need for additional research to understand the impact of grazing on the ecology of these resistance determinants in pasture-based cattle production. While E. coli remained higher in downstream water compared to upstream, MIG may reduce the magnitude of the downstream E. coli concentrations. Likewise, the MIG strategy may prevent large increases in TSS and NO3 + NO2-N concentrations during heavy rain events. Results indicate that MIG can limit the negative effects of cattle grazing on stream water quality.

Comparison of virtually fencing and electrically fencing sheep for pasture management

Context Virtual fencing technology has potential for application in intensive grazing management. However, it is unknown whether the presence of the virtual fence will affect the grazing behaviour of sheep under intensive grazing situations. Aims This study compared pasture consumption by sheep when pasture access is restricted using either a virtual fence (n = 12) or a conventional electric fence (n = 12), tested over three cohorts. Methods The sheep were given access to a small section of pasture (8 × 8 m) for approximately 4 h, over a total of 4 days of grazing, being moved onto a fresh plot each day. Within the grazing plot, average pasture dry matter, normalised difference vegetation index (NDVI), and rising plate meter (RPM) height, were measured before and after grazing. NDVI and RPM height were also measured along the fence line before and after grazing. Key results For within plot measures, there was no effect of treatment on biomass (P = 0.42), pasture height (P = 0.69) or NDVI (P = 0.72). The same was observed for measures taken at the fence line. The results of this study indicated that using a virtual fence to restrict access to pasture to create targeted grazing is as effective as using an electric fence. Conclusions The similarity in pasture consumption between the groups indicated that the virtual fence does not affect normal grazing behaviour of sheep, nor discourage them from grazing up to the fence line. Further work should be conducted in larger flocks and using automated systems. Implications Virtual fencing has the potential to be used to restrict sheep access to pasture to create targeted grazing that is as effective as is using an electric fence.

Silvopasture in the USA: A systematic review of natural resource professional and producer-reported benefits, challenges, and management activities

Silvopasture is the deliberate integration of trees, forage, and grazing livestock on the same piece of land. These agroecosystems are intensively managed for multiple benefits, providing both short- and long-term income. Research suggests that silvopasture systems can increase systemwide productivity, while providing multiple ecosystem services. Due to these benefits, silvopasture adoption is increasing across the United States of America (USA), as described in regional case studies exploring silvopasture adoption. However, most of these case studies have a limited sample size, making it difficult to assess broader trends that help or hinder silvopasture adoption. To address this issue, we conducted a systematic review of silvopasture adoption studies in the USA. Our key objectives were to understand the primary benefits and challenges reported by producers using silvopasture, assess how satisfied producers are with their silvopasture systems, and understand how agricultural and natural resource professionals view silvopasture management. In total, 53 studies from 1983 to 2021 related to silvopasture adoption were included. When analyzed collectively, diversification of farm income and shade for livestock were the primary benefits of implementing silvopasture. This was similar to benefits reported from international studies that were compared. Regarding challenges, lack of information was identified as a primary concern by producers. Producers reported using a wide range of livestock that included cattle, goats, sheep, chickens, turkeys, horses, bison, pigs, geese, and ducks. Results indicate that producers almost exclusively use some form of rotational or management intensive grazing in their silvopasture systems, with 98% using one of these practices. Furthermore, 96% of producers reported using silvopasture in combination with paddocks in open pasture, suggesting that silvopastures are primarily used as a complementary component of their pasture rotation system. Silvopasture retention was also found to be high across studies, with 88% of producers indicating they would continue the practice into the future. With increasing interest to diversify agricultural management under the uncertainty of a changing climate and the need for agricultural landscapes to sequester more carbon, silvopasture may be an effective strategy for some livestock operators to diversify farm income, enhance animal productivity and wellbeing, and increase ecosystem resilience.

Initial soil conditions outweigh management in a cool-season dairy farm's carbon sequestration potential

Pastures and rangelands are a dominant portion of global agricultural land and have the potential to sequester carbon (C) in soils, mitigating climate change. Management intensive grazing (MIG), or high density grazing with rotations through paddocks with long rest periods, has been highlighted as a method of enhancing soil C in pastures by increasing forage production. However, few studies have examined the soil C storage potential of pastures under MIG in the northeastern United States, where the dairy industry comprises a large portion of agricultural use and the regional agricultural economy. Here we present a 12-year study conducted in this region using a combination of field data and the denitrification and decomposition (DNDCv9.5) model to analyze changes in soil C and nitrogen (N) over time, and the climate impacts as they relate to soil carbon dioxide (CO2) and nitrous oxide (N2O) fluxes. Field measurements showed: (1) increases in soil C in grazed fields under MIG (P = 0.03) with no significant increase in hayed fields (P = 0.55); and (2) that the change in soil C was negatively correlated to initial soil C content (P = 0.006). Modeled simulations also showed fields that started with relatively less soil C had significant gains in C over the course of the study, with no significant change in fields with higher initial levels of soil C. Sensitivity analyses showed the physiochemical status of soils (i.e., soil C and clay content) had greater influence over C storage than the intensity of grazing. More extensive grazing methods showed very little change in soil C storage or CO2 and N2O fluxes with modeled continuous grazing trending towards declines in soil C. Our study highlights the importance of considering both initial system conditions as well as management when analyzing the potential for long-term soil C storage.

Understanding producers' perspectives on rotational grazing benefits across US Great Plains

AbstractExperimental findings on rotational grazing (RG) trials have generally differed from producer observations of RG outcomes on commercial scale ranches. Factors such as small plot size, short duration trials and relatively rigid grazing management that lacks responsiveness to the dynamic and complex social-ecological systems in grazing trials could all contribute to this disparity in outcomes. These differences call for a better understanding of producer perceptions of RG benefits. To fill this knowledge gap, we surveyed 4500 producers from the Northern and Southern Great Plains of the USA. Among the 875 respondents, 40.5% reported that they used continuous grazing (CG), 52.7% implemented RG management in an extensive manner, while 6.8% adopted management intensive grazing. Compared with CG users, adopters of RG in its extensive and intensive form reported an average annual increase of grazing season by 7.6 and 39.3 days, respectively. When controlling for producer demographics, ranch management goals and other rancher characteristics, we found soil and climate heterogeneity significantly affected the perceived relative benefits of RGvsCG strategies. Therefore, instead of focusing on whether RG outperforms CGper se, future research could focus on comparison of RG benefits under different management intensity levels and identifying soil and climate conditions where RG benefits are more noticeable.

Management intensive grazing on New England dairy farms enhances soil nitrogen stocks and elevates soil nitrous oxide emissions without increasing soil carbon

Management intensive grazing (MIG), also known as rotational grazing or multi-paddock grazing, is purported to sequester carbon (C) in soils compared to other agricultural management systems. Prior research examining the potential for MIG to enhance soil C has been inconclusive, and past investigations have not addressed whether higher nitrous oxide (N2O) emissions may accompany increases in soil C stocks. Here we examined linkages among MIG, soil C accumulation, and N2O emissions in cool-season, organic pastures of the northeastern United States. We found that pastures under MIG increased soil C concentrations by 11% from 0–15 cm depth but that soil C stocks at all sampled depths did not differ between hayed and grazed fields. We observed a divergent response in soil N to MIG, where both N concentrations and stocks significantly increased and the soil C:N ratio significantly decreased in rotationally grazed pastures. Our results also demonstrated that during the second year of the study, N2O emissions were on average 33% higher in grazed fields and compared to hayed fields. These elevated N2O fluxes in MIG fields may have offset any soil C gains achieved under MIG, as demonstrated by similar climate forcing values (as CO2-equivalents) for hayed and grazed pastures over a 100-year time horizon. The significant variation we detected among farms in soil C and N stocks, soil microbial activity, plant biomass production, and soil greenhouse gas emissions demonstrates that MIG does not have uniform effects across the landscape. Overall, our study demonstrates that care should be taken when promoting management practices that may have unintended climate consequences.

Sustainable intensification of livestock as a means to achieve forest conservation and food production in the Brazilian Southern Atlantic forest

ABSTRACT Brazil’s Atlantic Forest is a biodiversity hotspot. Efforts to restore the forest must address the tradeoffs facing family farmers. In this paper, we combine literature review and empirical analysis to evaluate the ways in which an agroecological practice – Management Intensive Grazing (MIG) – can contribute to sustainable intensification in southern Brazil. Our results show that farmers adopting MIG obtained, in general, better economic and environmental performance, but did not completely renounce the use of external inputs. Forest cover appears to have increased since the promotion of MIG and agroecology in the region and pasture area decreased, therefore, benefiting forest conservation.

Social-Ecological System Transformation and Learning: the case of Santa Rosa de Lima’s dairy system, Brazil

Abstract Conventional pastureland management has brought Southern Brazilian dairy farms to a financial and environmental crisis. In this context, the management-intensive grazing system (MIG) emerges as a viable alternative to conventional pastureland management. This study aims to analyze the Social-Ecological System (SES) transformation process of the dairy system in Santa Rosa de Lima, Southern Brazil, from conventional management to MIG. For the analysis, two different frameworks were combined: SES transformation process and the triple-loop learning frameworks. The analysis was based on a statistical analysis of interviews, conducted with dairy farmers. Results show that the dairy system in Santa Rosa de Lima is in the middle of a transformation process. During this phase, farmers have already reached single and, partially, double-loop learning. Among the elements needed to successfully move the transformation process forward, social learning stands out as indispensable, as well as financial capital. For this, payments for ecosystem services are suggested.

Intensive short-duration rotational grazing is associated with improved soil quality within one year after establishment in Colombia

Large-scale conversion of natural ecosystems to grazed grasslands and subsequent soil degradation due to overgrazing and inadequate pasture management in tropical agroecosystems urgently call for sustainable intensification of grazing systems, i.e. increasing animal productivity while maintaining or improving soil quality and ecosystem services. We investigated the impact of intensive short-duration rotational grazing (IRG) management on soil properties in two study sites in Colombian Eastern Plains. In each site, one farm with stocking rates as high as 4.2 livestock units (LU) ha−1 managed by IRG was compared with an adjacent traditionally managed (reference) farm with low animal stocking rate (1 LU ha−1), where cattle grazing was either continuous (Morichal site), or rotational with long grazing period and short periods of pasture recovery (Villasol site). As early as nine months after the adoption of IRG management, both farms managed by IRG had lower bulk density and higher water retention capacity than their respective reference farms, despite the more than four-times higher stocking rates. The animal feed supplement at the IRG farm at Morichal likely contributed to higher soil organic carbon stocks and improved soil aggregation when compared to the reference farm and to the Villasol site, where no supplement was applied. The improvement of soil properties found in IRG farms, compared to reference farms, was associated with a higher macrofauna abundance, particularly that of earthworms and beetles, which play a crucial role in soil structure improvement through bioturbation. Our results demonstrate the capacity of IRG management to intensify cattle production per unit area, while simultaneously improving soil properties and increasing soil macrofauna biodiversity as early as nine months since the implementation of IRG management.

Expanding grass-based agriculture on marginal land in the U.S. Great Plains: The role of management intensive grazing

Compared to conventional tillage-based crop production, grass-based agriculture can support substantially more ecosystem benefits. Moreover, management intensive grazing (MIG) has the capacity to enhance grassland resilience, thereby enhancing the profitability of grass-based agriculture. The research reported here is based on a survey of 4,500 producers in the Great Plains of USA, which aimed to study the role of grazing intensity on producers’ land use decisions. We received 875 completed questionnaires, representing a 20.6% response rate of 4,250 eligible sample. Results from multivariate ordered probit modeling analysis indicated that, compared to continuous grazing (CG) users, MIG users were 11% more likely to have expanded their grassland area in the past and 13% more likely to convert cropland to grassland in the next 10 years. Other factors, including higher cattle sales, greater liability ratio, poorer land quality and regional factors, were found to significantly influence producers’ intentions to purchase and lease more grassland. However, these factors were not significantly associated with the intention to convert marginal land to grassland. Therefore, the adoption of MIG appears to be a key factor for restoring marginal croplands to permanent grassland cover to enhance the environmental benefits across the Great Plains from the social perspective.

Getting the most out of your grass, strategies for implementation of Management-intensive Grazing (MiG)

To get the most out of grass (one should really say forage), producers need to comprehend some grazing related terminology, understand the basics of a managed grazing system, evaluate the natural resources available to the manager, understand that grazing management is some science and a great deal of art, realize that 1 system does not always fit, each grazing season is different and a learning opportunity, and know that often times the biggest road block to implementation of a grazing system is the gray matter that sits between our ears. This is a quick overview to get a producer thinking of what goes into a managed grazing system. There are a great many detailed resources available through local extension, in books, and from industry personnel.

Farming autonomy: Canadian beef farmers reclaiming the grass through management-intensive grazing practices

This qualitative study asks farmers in Alberta, Canada, what are their motivations for using a practice in beef production called management-intensive grazing (MIG). By adopting this practice, these farmers engage in strategies of diversification and co-production that increase the autonomy and resilience of their farms. MIG allows farmers to defy conventional agricultural practice and engage in what can be labelled a repeasantization process, a process that contributes to the discussion about conventional farming versus agroecology.

Social institution changes and their ecological impacts in Kazakhstan over the past hundred years

Over the past 100 years, the social system, agricultural production modes, lifestyles, and ecological conditions in Kazakhstan have changed dramatically. Understanding how social institution changes altered the land use patterns and the ecosystem processes in Kazakhstan can provide important knowledge for the sustainable ecological management of semi-arid regions. By summarizing the documented research on major social institution reforms, this study investigated land use changes in response to social system changes and analyzed the impacts of agricultural and animal husbandry development on ecological degradation. Three important characteristics of social-ecological system changes were found in this study. First, population migration, land policy changes, and social system reform were the major driving factors of ecological degradation, especially within the periods of Russian emigration in the early 20th century, the Virgin Lands Campaign, and the collapse of the Soviet Union. Second, changes in land use patterns caused by changes in social systems have led to a series of ecological degradation, especially the policy of collective management and regional intensive grazing. Land experiencing reclamation-abandonment-reclamation turbulence developed in a vicious cycle and eventually became a high-risk area of ecological degradation. Third, Kazakhstan experienced a long-term cultivated land expansion, occupying high-quality grassland and pastoral areas, which moved animal husbandry production to desert vegetation areas. The agro-pastoral transition zone in Kazakhstan was the mostly affected area by land use changes due to the social institutional changes and special attention is urgently needed to reduce land degradation and desertification.

Grazing-related nitrous oxide emissions: from patch scale to field scale

Abstract. Grazed pastures are strong sources of the greenhouse gas nitrous oxide (N2O). The quantification of N2O emissions is challenging due to the strong spatial and temporal variabilities of the emission sources and so N2O emission estimates are very uncertain. This study presents N2O emission measurements from two grazing systems in western Switzerland over the grazing season of 2016. The 12 dairy cows of each herd were kept in an intensive rotational grazing management. The diet for the two herds of cows consisted of different protein-to-energy ratios (system G: grass only diet; system M: grass with additional maize silage) resulting in different nitrogen (N) excretion rates. The N in the excretion was estimated by calculating the animal nitrogen budget taking into account the measurements of feed intake, milk yield, and body weight of the cow herds. Directly after the rotational grazing phases, background and urine patches were identified based on soil electric conductivity measurements while fresh dung patches were identified visually. The magnitude and temporal pattern of these different emission sources were measured with a fast-box (FB) chamber and the field-scale fluxes were quantified using two eddy covariance (EC) systems. The FB measurements were finally upscaled to the field level and compared to the EC measurements for quality control by using EC footprint estimates of a backward Lagrangian stochastic dispersion model. The comparison between the two grazing systems was performed during emission periods that were not influenced by fertilizer applications. This allowed the calculation of the excreta-related N2O emissions per cow and grazing hour and resulted in considerably higher emissions for system G compared to system M. Relating the found emissions to the excreta N resulted in excreta-related emission factors (EFs) of 0.74±0.26 % for system M and 0.83±0.29 % for system G. These EF values were thus significantly smaller compared to the default EF of 2 % provided by the IPCC guidelines for cattle excreta deposited on pasture. The measurements showed that urine patch emission dominated the field-scale fluxes (57 %), followed by significant background emissions (38 %), and only a small contribution of dung patch emission (5 %). The resulting source-specific EFs exhibited a clear difference between urine (1.12±0.43 %) and dung (0.16±0.06 %), supporting a disaggregation of the grazing-related EFs by excreta type in emission inventories. The study also highlights the advantage of a N-optimized diet, which resulted in reduced N2O emissions from animal excreta.