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This study aimed to evaluate the use of multiple covariates in robust geostatistical modeling of soil chemical properties characterized by the presence of outliers. Different spatial prediction methods were compared using data from two agricultural areas located in Brazil´s Southeast: one with rotational grazing and one cultivated with sugarcane. Considering the variable-rate fertilizer prescription in the context of precision agriculture, the use of multiple covariates for the prediction of four chemical soil properties (phosphorus (P), potassium (K), cation exchange capacity (CEC) and base saturation (V)) was evaluated. The covariates data set was divided into five categories representing soil, vegetation, relief, management of the area and geographic. Five methods were used: inverse distance weighting (IDW), robust multiple linear regression (RMLR), robust ordinary kriging (ROK), robust universal kriging with spatial co-ordinates in the trend (RUKcoord) and robust universal kriging with environmental and management covariates in the trend (RUKcovars). The model based on the mean was used as a null reference. In general, the use of covariates in robust prediction methods improves the accuracy of spatial prediction of soil properties in the presence of outliers. However this effect was not observed in all situations, depending on the dataset characteristics and the spatial variability of the fields. The management practices are important information for modeling the trend in digital soil mapping for fertilizer prescription purposes. RMLR produces prediction results that are, at least, equivalent to that of robust geoestatistics. [ABSTRACT FROM AUTHOR]

• Soil physical properties were investigated in response to grazing. • Grazing caused a noticeable increase in the soil penetration resistance. • Soil physical quality was reduced due to compaction. • Decrease in physical quality can be noticed after two grazing periods. Soils in areas under grazing undergo physical changes, of greater or lower intensity, by the action of animal trampling. Thus, the objective of this study was to evaluate the spatial dependence of the physical attributes and associated soil functionalities under trampling by cattle on rotational grazing in the region of Pernambuco, Brazil. The research was conducted at the Experimental Farm of the Federal Rural University of Pernambuco, Agreste region of the State of Pernambuco, Brazil. In the field, a paddock of 0.25 ha was demarcated and four crossbred dairy cattle (Holstein-Zebu) with an average weight of 450 kg were used, managed in a rotational grazing system that included 7 days of occupation and 28 days for pasture rest. Undisturbed soil samples were collected before the first passage of the animals in the paddock and at the end of each pasture rest period, i.e., at 0, 35, 70 and 105 days of study, in a 6 × 14 m mesh, which totalled 32 sampling points. At each point, bulk density (BD), total porosity (TP), water content (W), soil penetration resistance (PR) at depths of 0.00–0.10 and 0.10–0.20 m and the soil saturated hydraulic conductivity (K 0) were determined. The data obtained were submitted to descriptive, geostatistical and multivariate statistical analysis (canonical discriminant analysis). After a period of 105 days of grazing, at both evaluated depths, an increase in the average values of PR and BD and a reduction in the values of TP, K 0 and W was observed. Normal distribution was observed in all variables studied. The physical attributes of the soil presented a coefficient of variation between low and medium and strong spatial dependence in both grazing periods. The canonical multivariate analysis indicated a reduction in the soil physical quality, especially after the animals' second passage in the paddock. [ABSTRACT FROM AUTHOR]

Context: Integrating trees and pastures can provide benefits to grazing animals in warm climates, such as provision of shade during the excessive heat. Aim: Our aim was to evaluate the effects of two arrangements of trees on grass production and behavioural, physiological and blood parameters of crossbred lambs grazing massai grass (Megathyrsus maximus) pastures in a tropical environment in São Paulo state, Brazil. Methods: Two groups of 24 Santa Inês × Dorper male lambs (~90 days old, 24.0 ± 3.3 and 22.0 ± 2.4 kg bodyweight, respectively) were used in two growing seasons, stratified by initial bodyweight and randomly assigned to one of three treatments: unshaded massai grass (no shading, NS), moderate shading (MS), or intense shading (IS). Treatments MS and IS were established with single rows of eucalyptus trees at spacing 12 m or 6 m between rows and 2 m within rows, corresponding to 786 and 1190 trees/ha. Each growing season consisted of two grazing cycles of ~20 days each, when tester animals grazed simultaneously in a rotational stocking system with variable stocking rate. Behavioural observations were feeding, lying ruminating, standing ruminating, lying, standing still, searching for food, and other. Physiological measurements were rectal temperature, respiratory frequency and heart rate. Blood parameters included haemogram, acute-phase proteins and serum cortisol concentrations. Key results: Animals under treatment IS spent more time (P < 0.05) lying, standing still and at other activities than animals under NS and MS. Moreover, they presented lower rectal temperature and respiratory and heart rates than animals under NS during the first growing season, which was the season with higher temperatures. Cortisol and acute-phase proteins were not affected by treatment. Conclusions: When animals were exposed to sun, the silvopastoral system was efficient for avoiding heat stress; however, the density of trees reduced the forage mass. Implications: The silvopastoral system is a viable alternative production system in warm climates to improve the welfare of sheep, but the density of trees must be considered so that it does not negatively influence the forage mass. Integrating trees and pastures can provide benefits to grazing animals in warm climates, such as provision of shade during the excessive heat. When animals were exposed to sun, the silvopastoral system was efficient for avoiding heat stress; however, the density of trees reduced forage mass production. Therefore, silvopasture is a viable alternative production system in warm climates because ruminants with improved thermal comfort will drive energy that is otherwise wasted in thermoregulatory processes to preferred activities such as grazing and ruminating. [ABSTRACT FROM AUTHOR]

The insertion of the animal component into the crop production system can alter the nutrient dynamics and, consequently, the soil fertility status over time. This change occurs differently according to the arrangement adopted, depending on both, the intensity and frequency of animal grazing, as well as the crop rotation system. This study was carried out aiming to evaluate the effect of sheep grazing intensity and frequency during the winter period and the crop rotation in the summer period on the (i) temporal evolution and vertical distribution of soil chemical properties, and (ii) on the nutrient (phosphorus – P, potassium – K, calcium – Ca, and magnesium – Mg) budget. The experiment was established in 2003, in a subtropical Acrisol in southern Brazil, arranged in a randomized block design with split plots. The treatments were two grazing intensities (moderate and low), two stocking methods (continuous and rotational), subdivided into two crop rotation systems (monoculture - soybean/soybean and crop rotation soybean/maize). Temporal variation of soil pH, exchangeable aluminum (Al), Ca and Mg, available P and K, base saturation, Al saturation, and cation exchange capacity (CEC) were evaluated in samples collected in 2003, 2010, 2015 and 2017, corresponding to 0, 7, 12 and 14-years after the beginning of the experiment. The vertical distribution (0–5, 5–10, 10–20, 20–30 and 30–40 cm) of these chemical properties were also evaluated 14-years after the beginning of the experiment (2017). The nutrient budget in the soil was calculated based on the initial and final available/exchangeable contents in the 0–10 cm soil layer and the inputs (fertilizers) and outputs (exportation by grain and meat) of nutrients. >95% of P, K, Ca and Mg were exported by grains and <5% by sheep meat. There was an intense acidification of the soil over the 14-years of experiment as shown by the decrease of soil pH and base saturation, and the increase of Al saturation. Crop rotation with soybean/maize increased CEC up to 5 cm soil depth and increased the available K content up to 40 cm soil depth. The available K budget was more negative in soybean monoculture due to higher grain exportation. Integrated crop-livestock system involving low grazing intensities and rotational stocking methods, coupled with crop rotation in the summer, was more efficient in the use of nutrients. • Monoculture of soybean decreases available K in the soil. • Rotational animal stocking method results in a more efficient use of nutrients. • The animal is the component that controls nutrients recycling in the system. • The grain crops are the components that control soil nutrient budget. • 95% of the nutrients were exported by grains and <5% by sheep meat. [ABSTRACT FROM AUTHOR]

• Higher residual leaf area index (rLAI) of Tifton 85 provides higher forage allowance. • Use of supplementation for sheep in the rainy season increases the stocking rate. • Leaf area index associated with pasture height can be used for pasture management. • Higher rLAI favors higher gain per animal in Tifton 85 in the rainy and dry seasons. This study evaluated the structural and production characteristics of Tifton 85 (Cynodon spp.) pastures and the performance of lambs under different residual leaf area index (rLAI) and supplementation strategies in tropical conditions. Treatments were the factorial combination of 4- rLAI (0.8; 1.4; 2.0 and 2.6) and 2-supplementation strategies with four replicates in a randomized complete block design. The study was divided into two periods in southeastern Brazil: one in the rainy season and the other in the dry season. Lambs grazed under rotational stocking management and they grazed for 4 days in each pasture while pasture regrowth period was determined by the 95% light interception requirement. In the two evaluated periods the resting period and herbage accumulation decreased linearly and herbage allowance increased linearly with increasing rLAI. The chemical composition and digestibility were affected by rLAI only in the dry season. The dietary supplementation in the rainy season promoted increase of the gain per area but in the dry season the types of supplements did not promote changes in the animals performance. In the rainy season Tifton 85 pastures in rotational stocking can be managed with rLAI between 2.0 and 2.6 with approximately 18 days of regrowth period, and in the dry season with rLAI between 1.4 and 2.0 equivalent to the pasture regrowth period from 58–65 days. [ABSTRACT FROM AUTHOR]

Cattle ranching in Brazil is a key driver of deforestation and greenhouse gas (GHG) emissions. The Brazilian government plans to reduce national GHG emissions by at least 36%, partly by reducing emissions in the livestock sector through strategies such as intensification, pasture improvement, and rotational grazing. In response, sustainability programs promoting these practices have begun operation. Though studies have previously investigated aspects of GHG emissions and sequestration in improved pastures, they have not linked improvements with programmatic interventions. We surveyed 40 cattle ranchers located in the Brazilian Amazon biome to investigate how GHG emissions differed between farms participating in livestock sustainability programs with intensified production and farms not participating in these programs. We found that participating farms produced 8.3 kg of CO 2 e/kg of carcass weight (CW) less than did non-participating farms, which represents 19% fewer emissions. Farms that had participated in a sustainability program for at least two years showed larger differences in emissions: 19.0 kg of CO 2 e/kg CW less for program farms compared with their counterparts, or 35.8% fewer emissions. Key drivers of the total CO 2 e/kg CW in all farms were enteric fermentation and manure management. This paper provides farm-level data supporting intensification as a possible strategy to reduce emissions per kilogram of beef produced, and suggests that future research efforts should focus on long-term impacts of intensification and expand metrics for success beyond GHG calculations. [ABSTRACT FROM AUTHOR]

Livestock production in pastures have deserved increasing interest in modern society, which is more concerned about environmental issues. This study aimed to validate the use of geoprocessing tools to aid the planning, implementation and utilization of intensive pasture systems in order to boost plant growth and prolong the period of use of pasture with better quality, ensuring not only greater income to the producer, but also increased conservation and recovery of grazing lands. This work was conducted in the city of Viamão, RS, Brasil, from June to November 2011, in areas with different uses (pastures, grasslands, reforestation areas). The GPS receivers were employed to survey points of the field. The data files were downloaded in TrackMacker® software to elaborated planimetric maps, performed with the help of GOOGLE EARTH® program. Then, the latitude, longitude and altitude were interpolated in software GOLDEN SURFER® 10, obtaining, thereby, planialtimetric maps. Based on these information, we made the subdivision of the pastures, considering the effective grazing surface, land slope and the access to water. We also defined exclusion areas; selected points for installation of new areas of water; collected soil material; and observed three cycles of use (an average of two days of permanence, followed by twenty days of rest) from different areas. These tools do not exclude the need for direct observation and monitoring, however, when they are properly employed, they act as facilitators, enabling a faster and more accurate management decisions. [ABSTRACT FROM AUTHOR]

Pasture management techniques may affect the biodiversity of insects beneficial to pastures, such as dung beetles. Cattle grazing removal over a short-term is widely used in introduced Brazilian pastures. However, the impact of this management on dung beetles is still unknown. This study evaluated the taxonomic (species richness, abundance, biomass, species composition, Shannon, and Simpson indexes) and functional (functional richness FRic, functional dispersion FDis, functional evenness FEve, and community-weighted means of trait values CWMs) dung beetle assemblages response to cattle grazing removal over a short-in introduced pastures. We sampled dung beetles, with pitfall traps baited with cattle dung and carrion, simultaneously in pastures with constant cattle grazing (control), and one, three, and five months after cattle grazing removal in Aquidauana, Mato Grosso do Sul, Brazil. Taxonomic metrics and FRic, FDis, and FEve did not differ among control and pasture treatments. We found that pastures with one month of cattle removal maintain the same CWM coprophagous diet from the control, and higher CWM biomass in relation to control. Although cattle grazing removal, at least over the short-term, does not cause a negative impact on dung beetle taxonomic metrics and functional diversity indexes, two important traits associated to dung removal are negatively affected after three months of cattle removal. Thus, we suggest that one month of cattle removal to grazing rotational management in introduced Brazilian pastures can be a useful strategy to, besides conserving the grass, also conserving dung beetle diversity, and consequently the ecological functions performed by them. • We study the effects of cattle removal on dung beetles in introduced Brazilian pastures. • Taxonomic metrics and functional diversity indexes were not affected by cattle removal. • Biomass and coprophagous diet (traits) decrease after three months of cattle removal. • One month of cattle removal is adequate to conserve dung beetles in introduced pastures. [ABSTRACT FROM AUTHOR]

• The intensity of grazing affects soil air permeability. • Grazing exclusion allows recovery of soil structure, improving pore connectivity. • As grazing intensity increased, soil air permeability decreased. • The correlation of air-filled porosity versus air permeability may indicate pore connectivity. The expansion of dairy farming in southern Brazil, mainly under a rotational grazing system, has generated soil physical changes with loss of soil quality, which in turn must be evaluated to determine how long they persist and how the soil recovers from these changes. The objective of this study was to evaluate the natural recovery of the soil physical attributes of a clayey Oxisol (Latossolo Vermelho distrófico típico, with clayey texture), which had been managed under different intensities of dairy cattle grazing: T0 = no grazing, T30 = consumption of 30 % of available forage, T50= consumption of 50 % of available forage and T80= consumption of 80 % of available forage. The rotational grazing system consisted of a grazing period (an average of 4 h) with a variable stoking rate to achieve forage consumption. For T0, zero animals, T30 three animals, T50 six animals and T80 nine animals per 100 m2 plot were used, followed by animal exclusion until the forage reached an average height of 35 cm. The grazing system was conducted for approximately 7 months, after which the animals were permanently removed from the area. The recovery of soil physical properties was monitored by soil sampling every three months for one year. The evaluated soil physical properties were porosity, bulk density and air permeability. The increase in grazing intensity negatively affected the soil physical quality. At all grazed areas, T30, T50 and T80, there was a reduction of the total porosity, the macroporosity and the soil air permeability, as well as an increase of the soil bulk density compared with the no grazed area, T0. However, 90 days after exclusion, increases in total porosity and macroporosity were observed. The angular coefficient between soil air-filled porosity and air permeability decreased as the grazing intensity increased and increased with time after grazing exclusion. Rotational grazing areas, when managed properly, can be an important tool for sustainable production. The use of grazing exclusion periods alleviates compaction, reducing the risk for forage production for the following grazing season. [ABSTRACT FROM AUTHOR]

• Grazing intensity did not affect the ecosystem water balance at the annual timescale. • Vegetation biomass was strongly affected by grazing intensity. • Maximum cattle weight was reached after the peak of rainfall and vegetation growth. • Hydrology-vegetation-livestock interactions are sensitive to rainfall fluctuations. • Tradeoffs occur between water input, vegetation biomass, and animal weight. Climate change will likely trigger shifts in rainfall regimes that may intensify water scarcity in semi-arid regions. In the semi-arid region of Brazil, the seasonally dry ecosystem is the primary source of forage for livestock. Because the correct stocking rate of livestock (animals per area) is not well understood, overgrazing tends to advance rangeland degradation in this ecosystem. This implies that the region may become even more vulnerable under changing rainfall regimes, which in turn may exacerbate livestock and food insecurity. We developed a coupled soil water balance, vegetation, and cattle biomass model to illustrate the impacts of rainfall seasonality on the dynamics of vegetation and animal growth. The outcomes were simulated by considering different stocking rates and the timing of animal placement and removal from the rangeland. A more pronounced reduction in vegetation biomass was found in grazed vs. non-grazed paddocks. Under strongly seasonal rainfall patterns, the maximum animal weight gain decreases with average rainfall inter-arrival time and increases with total annual rainfall. Thus, a forecast of dry spells could benefit farmers in planning grazing management strategies. Our model can be used to test different management scenarios and give feedback for local herders, and to guide future experiments to reduce the time and cost of acquiring data. [ABSTRACT FROM AUTHOR]

Schematic map of carbon and nitrogen inputs in the soil via crop and pasture residues and the respective carbon and nitrogen stocks in the 0–30 cm soil layer influencing maize yield in Southern Brazil. • Grazing intensity and stocking method effect on soil C and N stock were evaluated. • Low grazing intensity resulted in higher soil C and N stocks in long-term. • Residues quality (C:N ratio) played a key role in soil C accumulation. • Higher soil N stocks in low grazing intensity favored maize yield. Integrated crop-livestock systems (ICLS) conducted under no-tillage have been shown to favour the accumulation of carbon (C) and nitrogen (N) in soil. In that systems, however, C and N accumulation in soil might depend on pasture management and the type of crop rotation used. The objective of this study was to evaluate the impact of two stocking methods (continuous and rotational) and two sheep grazing intensities (moderate and low) on winter pasture and the effect of summer crop rotation (soybean and/or maize) on crop yield and C and N stocks in an Acrisol after 14-yr under experimental conditions. The evaluated ICLS was set up for grain yield in the summer crop phase and for sheep meat production in the winter pasture phase. Pasture production, soybean and corn yield were evaluated throughout the experimental period. After 14-yr, the soil was sampled at the 0–5, 5–10, 10–20 and 20−30 cm layers to evaluate the content and stock of C and N. Higher C and N contents in soil superficial layers (0–5 and 5–10 cm) were observed under low grazing intensity in winter and soybean monoculture in summer. The C and N stocks in 0−30 cm soil layer ranged between 39 and 45 Mg C ha−1 and 4 and 5 Mg N ha−1, respectively. C and N stocks in the soil were significantly related to N added through the residues of pasture and summer crop. This positive relationship is possibly explained by the higher efficiency of microbes in using crop residues enriched in N with posterior stabilization of microbial residues through organo-mineral association in the soil. The higher content and stocks of C and N associated with low intensity grazing favoured a higher maize yield (40%) compared to moderate grazing intensity in the 2015/2016 season. According to our results, the accumulation of C and N in the soil under ICLS involving low grazing intensity in the winter and soybean monoculture in the summer was related to the N added/recycled by the soybean and by the hibernal pasture. [ABSTRACT FROM AUTHOR]

Cattle dung distribution in pastoral ecosystems is uneven and affects nutrient availability to plants. Thus, identifying its spatiotemporal patterns is crucial to understanding the mechanisms underlying the system functioning. We aimed to characterize the spatiotemporal distribution of dung patches in mixed black oat (Avena strigosa Schreb.) and Italian ryegrass (Lolium multiflorum Lam.) pastures grazed at different intensities (sward heights of 0.1, 0.2, 0.3 and 0.4 m) in the winter stocking period of an integrated soybean-beef system in southern Brazil. All dung patches were located and georeferenced every 20 days. Dung distribution was analyzed using Thiessen polygons and semivariogram analysis. The spatial pattern of dung deposition was virtually similar over time but created distinct patterns in paddocks managed at different grazing intensities. Dung patch density was greater close to attraction points, resting and socialization areas regardless of grazing intensity. Lighter grazing intensities presented stronger spatial patterns with increased dung density in those areas, but those patterns weakened with increasing grazing intensity. Dung patches covered 0.4%, 0.9%, 1.1% and 1.5% of the area in paddocks managed at 0.4, 0.3, 0.2 and 0.1 m sward heights, respectively. Geostatistics proved useful for identifying spatial patterns in integrated crop-livestock systems and will potentially support further investigations. [ABSTRACT FROM AUTHOR]

Fast and accurate quantification of the available pasture biomass is essential to support grazing management decisions in intensively managed fields. The increasing temporal and spatial resolutions offered by the new generation of orbital platforms, such as Planet CubeSat satellites, have improved the capability of monitoring pasture biomass using remotely sensed data. Here, we assessed the feasibility of using spectral and textural information derived from PlanetScope imagery for estimating pasture aboveground biomass (AGB) and canopy height (CH) in intensively managed fields and the potential for enhanced accuracy by applying the extreme gradient boosting (XGBoost) algorithm. Our results demonstrated that the texture measures enhanced AGB and CH estimations compared to the performance obtained using only spectral bands or vegetation indices. The best results were found by employing the XGBoost models based only on texture measures. These models achieved moderately high accuracy to predict pasture AGB and CH, explaining 65% and 89% of AGB (root mean square error (RMSE) = 26.52%) and CH (RMSE = 20.94%) variability, respectively. This study demonstrated the potential of using texture measures to improve the prediction accuracy of AGB and CH models based on high spatiotemporal resolution PlanetScope data in intensively managed mixed pastures. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the grazing behaviour of F1 Boer x Saanen goats maintained in a tropical pasture (Panicum maximum Jacq), under rotational grazing system in different sward structure. The area was divided into 12 paddocks of 990 m2 each, allocated in six blocks. Each paddock was divided into two identical plots (treatments, TRT) with high residual (HR, 3.1 t/ha of green herbage mass; GHM) and low residual (LR, 2.0 t/ha GHM). Each plot was grazed for three consecutive d (D1, D2 and D3) before animals were rotated. Grazing time (GT, min) was recorded during daytime (0700 to 1900 h) and behavior was observed every 10 min, with four animals per TRT. Bite rate (BR, bites/min) was the total number of bites during three minutes, and bite mass (BM, g/bite) was estimated with esophageally fistulated animals. Measurements were conducted during three consecutive grazing cycles of 36 d. The mean stocking rate for HR was 33 goats/ha (or 6.6 animal unity (AU)/ha) and for LR was 43 goats/ha (or 8.4 AU/ha). The GT increased from D1 to D3 (468, 491 and 535 min for D1, D2, D3) in the LR, but did not differ in the HR (468 min). BR did not differ between treatments (P=0.12) or among days (P=0.42), and averaged 80.3 bites/min. In contrast, BM was higher (P=0.01) in HR (0.18 g/bite) than in LR(0.15 g/bite), and decreased from D1 to D3 (0.22; 0.16 and 0.11 g/bite). These differences can be explained by the low herbage allowances in the LR. We observed the functional relationship between BM and GT, in which the animal increased the grazing time to offset the lower BM. Our findings are consistent with the general assumption that BM are greatest during the first day, as a result of the trade-off between quantity and quality of the herbage mass. a Sponsored by FAPESP and CNPq, Brazil. [ABSTRACT FROM AUTHOR]