Integrated Crop-livestock Systems Research Articles

Contribution of Integrated Crop Livestock Systems to Climate Smart Agriculture in Argentina

Integrated crop-livestock system (ICLS) is a useful practice to enhance soil organic carbon (SOC) compared to continuous cropping systems (CC). However, robust data from different regions around the world remain to be collected. So, our objectives were to (i) compare SOC and its physical fractions in ICLS and CC, and (ii) evaluate the use of δ13C to identify the source of C of SOC in these systems in the Pampas region of Argentina. For that, we compared two farms, an ICLS and a CC having the same soil type and landscape position. The ICLS farm produces alfalfa grazed alternatively with soybean and corn, and the CC farm produces the latter two crops in a continuous sequence. Soil samples (0–5, 5–20, 20–40, and 40–60 cm) were collected and analyzed for SOC, its physical fractions, and their isotopic signature (δ13C). Soils under ICLS showed an increment of 50% of SOC stock compared to CC in the first 60 cm. This increase was related to 100–2000 µm fractions of SOC. The shift in δ13C signature is more in ICLS than in CC, suggesting that rotation with C3 legumes contributed to C sequestration and, therefore, climate-smart agriculture. The combination of on-farm research and isotopic technique can help to study deeply the effect of real farm practices on soil carbon derived from pasture.

Phosphorus fractions and their relationships with soil chemical attributes in an integrated crop-livestock system under annual phosphates fertilization

The main factors affecting phosphorus (P) availability in soils are mineralogy, acidity, and concentration of elements in the soil solution. Moreover, P fertilizer sources and amounts can affect P cycling and adsorption of this element on colloids. In this research, we hypothesized that the use of phosphate sources of different solubilities can alter soil P adsorption process, due to chemical compositions of these sources and, in ICLS, the soil-plant-animal system can change the P forms distribution on soil profile and its interactions with the soil chemical attributes. To examine these hypotheses, a field experiment was conducted over 5 years, under a Haplic Cambisol, in an incomplete factorial scheme, with the treatments being composed of three P sources (triple superphosphate, rock phosphate—Arad and magnesium thermophosphate), three doses of total P2O5 (60, 120, and 180 kg ha−1) plus a treatment without application of phosphate fertilizer. Phosphate applications occurred annually, broadcast without incorporation, at the time of sowing the annual winter forage, in a crop rotation system that included pasture in autumn-winter and grain crops in spring-summer. Soil samples were collected at depths of 0 to 5, 5 to 10, 10 to 15, 15 to 20, and 20 to 30 cm and evaluated by Hedley P fractionation and the soil chemical attributes were quantified. The use of different phosphates applied broadcast without incorporation did not influence the concentrations of soil P fractions over a 5 year study. Phosphate fertilizer doses above 120 kg ha−1 of total P2O5 increased moderately labile and non-labile P fractions. The highest concentration of labile P was found up to 15 cm soil depth. It was found that P lability is strongly associated with calcium and total organic carbon concentrations in the soil profile. High concentrations of basic cations and sulfate in the soil solution increased moderately labile and non-labile P fractions. The complexity of ICLS interactions to maintain phosphorus dynamics in the soil was shown to be an intricate P release/adsorption process associated with soil chemical attributes.

Intensification and diversification of pasturelands in Brazil: Patterns and driving factors in the soil carbon stocks

The extensive system of pasture management in Brazil can reduce soil C stocks and increase CO2 emissions to the atmosphere. However, the adoption of sustainable management systems can change these conditions and enact modern practices of natural resource management as defined by the concept of ecosystem services. A field study was therefore carried out to assess the effects of adopting more intensive and diversified systems of pasture management on the quality and stocks of soil C. Treatments included fertilized pasture (FP), integrated crop-livestock (ICL), and integrated livestock-forest (ILF) and were compared to conventional management systems (CS) under different soil and climate conditions (tropical humid, subtropical dry and subtropical humid). Soil carbon stocks and soil organic matter (SOM) fractions were determined in the top one-meter layer. With the SOM fractions, we calculated the C lability (LI), pool (CPI) and management (CMI) indices. The results showed that adopting ICL systems under the conditions of a tropical humid and subtropical humid climate produced increases in soil C stocks of 0.75 Mg ha−1 yr−1 (P < 0.01) and 0.15 Mg ha−1 yr−1 (P < 0.05), respectively, relative to the CS. Similarly, the conversion of a CS to FP (tropical humid climate) and ILF (subtropical dry climate) led to increases in soil C stocks of 2 and 0.55 Mg ha−1 yr−1 (P < 0.05), respectively. In general, the adoption of more intensive and diversified systems of pasture management can also afford increases in the LI, CPI and CMI indices. These results can serve as a scientific basis for government initiatives that focus on recovering degraded pastures in Brazil through the use of more sustainable management systems and can also help to sequester more C in soils.

Carbon estimation in an integrated crop-livestock system with imaging sensors aboard unmanned aerial platforms

Biomass and carbon estimates in integrated crop–livestock (iLP) systems remain scarce. Recently, sensors aboard an unmanned aerial vehicle (UAV) have been used for such estimation and can represent an efficient and low-cost method for acquiring accurate remote-sensing data. This study aimed to estimate the relationship between vegetation indices (VIs) and carbon stock in an upland rice field intercropped with Brachiaria, an exotic grass species in the savanna ecosystem of Brazil (Cerrado biome), using multispectral aerial imaging with a high cartographic scale. The research was conducted in an experimental iLP system located at the Brazilian Agricultural Research Corporation (Embrapa Arroz e Feijão), Goiás State. During the data collection stage, flights were conducted with a fixed-wing UAV (eBee Plus RTK) on the same day or close to collecting biomass samples in the field. In the processing step, a correlation was performed between the normalized difference vegetation index (NDVI), simple ratio (SR), soil-adjusted vegetation index (SAVI), and modified photochemical reflectance index (MPRI) VIs and the biomass measured in the field. The results indicated that the vegetation index (VI) that used the near-infrared (NIR) band showed a stronger correlation with biomass than the VI that used only the visible band information. All VIs were significantly correlated with the estimated field biomass (P < 0.05) using Pearson's correlation. The regression models were able to predict the biomass and carbon stock in Phase 1 (3.93 Mg ha−1, 1.66 Mg ha−1, R2 = 0.748) and Phase 2 (7.53 Mg ha−1, 3.19 Mg ha−1, R2 = 0.816). From the best model selected for each phase, maps with the spatial and temporal distribution of the biomass of the iLP system were plotted, demonstrating one of the advantages of employing remote sensing techniques based on drones and multispectral imaging sensors.

System Fertilization Increases Soybean Yield Through Soil Quality Improvements in Integrated Crop-Livestock System in Tropical Soils

System Fertilization Increases Soybean Yield Through Soil Quality Improvements in Integrated Crop-Livestock System in Tropical Soils

Phosphorus lability in a subtropical Acrisol under long-term integrated crop-livestock system: impacts of grazing management and cropping system

Studies on lability of soil phosphorus (P) under integrated crop-livestock systems (ICLS) are still scarce, especially for deep soil layers (more than 0.20 m depth) and different managements in the crop and livestock phase. Distinct management in these phases may lead to a different distribution of soil P pools according to its lability (labile, moderately labile, less labile and residual) and, consequently, the P availability for plant nutrition. This study aimed to determine the soil P pools, by P [...]

Growth and productivity of Eucalyptus benthamii in integrated crop–livestock systems in southern Brazil

Growth and productivity of Eucalyptus benthamii in integrated crop–livestock systems in southern Brazil

Sheep in the Vineyard: Suitability of Different Breeds and Potential Breeding Objectives.

Simple SummaryThere is a large number of sheep breeds worldwide. Today, many of them are endangered, because there are very little market demands for the majority of breeds. The integration of sheep in viticultural systems offers a promising option to put sheep and unique breed characteristics in value. However, it is unknown which characteristics and breeds are best suited for this purpose. The lack of information leads to problems in the implementation of this so-called new integrated crop-livestock system. In our research, we addressed this challenge. We studied 26 breeds and tested their suitability for integration into common vineyards of Central Europe. Two breeds fulfill the most important requirement. Southdown and Shropshire, for the latter especially, the sheep of the shorter legged Danish type seem to be unable to stand on two legs. Their muzzle heights stay within a tolerable range without harming the foliage area of vines. Therefore, adult animals of both breeds seem suitable to take over important viticultural tasks during the growing season. A third breed, the Ouessant sheep, is suitable with some limitations.Protecting a breed of sheep is simple when there is demand for its breed traits, but new market options are often hard to find. In general, grazing sheep are able to take over some viticultural work. Here, we address a new and promising integrated crop-livestock system that involves the integration of sheep in the vineyard during the growing season. Using sheep in a vineyard entails opportunities but also risks, such as the current lack of information, specifically in relation to breed traits. In our survey, we evaluated 26 breeds for their suitability for grazing as long as possible in Central European vineyards during the growing season. First, the breed traits required were identified. Then, 94 flock book breeders were interviewed about specific breed traits. The height of a sheep’s muzzle is particularly important for assessing the suitability of a breed, as it defines the potential impact on the foliage area during the growing season. To determine the height of the muzzle, 179 flock book animals were measured. We found that the most important breeding objective for a new breed of sheep is the inability to stand on two legs. Adult animals of the breed Shropshire, and among these especially the shorter-legged Danish type, and Southdown, show a widespread inability to stand on two legs. Ouessant sheep are able to do so, yet are suitable with some limitations. Due to their extraordinarily small size, their reach is limited, as is their grazing performance. Thus, three of the 26 breeds studied here seem suitable for use in the most widespread vine training systems of Central Europe during the growing season. Targeted breeding could further improve the suitability of sheep for viticulture. Our findings could help to protect breeds and breed traits.

306 Cattle Performance and Forage Nutrients While Grazing an Integrated Crop-Livestock System Compared with Grass Pasture in the Northern Great Plains

Abstract Many integrated crop-livestock system (ICL) studies have been conducted, but few report cattle performance and forage nutrients. Here, we report one year of cattle weight gains for Angus yearling heifers and steers grazing ICL plots (ICL) or tame grass pastures (PAS) in four replicates. Five yearlings (avg. BW 390 ± 26 kg) were randomly assigned to graze each plot while provided ad libitum water and trace mineral salt. Cattle assigned to ICL grazed three crop rotations: 1) corn interseeded with soybean (C/S), 2) spring wheat interseeded with cover crop and 3) cover crop planted into spring wheat from the previous year. Yearlings in ICL were stocked first on green C/S, grazing an average of 60 days. Beginning C/S biomass was 1,827 ± 638 g m−2, yearling end BW was 465 ± 34 kg and ADG 1.28 ± 0.27 kg. Yearlings then grazed residual cover crop growth, averaging additional 42 d grazing while supplemented with a ration of baled cover crop forage, wheat straw, and corn. Ration intake averaged 15.35 ±0.6 kg animal-1 d-1. Final BW of ICL yearlings on cover crops averaged 499 ± 34 kg, ADG of 0.79 ± 0.29 kg. Yearlings assigned PAS were provided 1,911 ± 162 g m−2 at the beginning of grazing for 69 days, had final BW 443 ± 35 kg, ADG of 1.01 ± 0.22. Forage nutrient analyses are reported in Table 1, showing that individual crops are similar in ADF and TDN, but vary in crude protein content. Performance of ICL cattle exceeded that of PAS while on corn and soybean but decreased ICL performance while grazing cover crop was likely due to extreme cold weather at the time of grazing. Nutrient values reported here can be used to plan and predict cattle growth while grazing crop residues instead of pastures.

Nitrous Oxide Emissions from a Long-Term Integrated Crop–Livestock System with Two Levels of P and K Fertilization

Nitrous oxide (N2O) emissions resulting from nitrogen (N) fertilization have been documented. However, no data on the effects of other nutrients, such as phosphate (P) and potassium (K), on N2O emissions in integrated crop–livestock systems are available so far. In the 2015/2016 and 2016/2017 growing seasons, we measured N2O emissions from a long-term system, established in 1991 in the Cerrado biome (a tropical savanna ecoregion in Brazil), fertilized with two P and K levels. The studied no-tillage farming systems consisted of continuous crops fertilized with half of the recommended P and K rates (CC-F1), continuous crops at the recommended P and K rates (CC-F2), an integrated crop–livestock system with half of the recommended P and K rates (ICL-F1), and an integrated crop–livestock at the recommended P and K rates (ICL-F2). The cumulative N2O emissions (603 days) and soil chemical properties were analyzed as a 2 × 2 factorial design (long-term agricultural systems x fertilization). The cumulative N2O emissions from CC-F2 and ICL-F1 were 2.74 and 1.12 kg N ha−1, respectively. The yield-scaled N2O emissions from soybean were 55.5% lower from ICL-F1 than from CC-F2 in the 2015/2016 growing season. For off-season sorghum, the mean yield-scaled N2O emissions were 216 mg N2O m−2 kg−1 (in a range from 79.83 to 363.52 mg N2O m−2 kg−1, for ICL-F2 and CC-F1, respectively). The absence of pasture and the presence of soybean and sorghum promoted the highest cumulative N2O emissions, favored by the recommended rate in relation to half of the P and K. In the total evaluation period (603 days), the presence of grazed land in the years prior to this study and land fertilized with half the recommended P and K rates in an integrated crop–livestock system reduced the resulting cumulative N2O emissions by 59%. Thus, we conclude that crop–livestock systems can be beneficial in reducing P and K applications and also in mitigating N2O emissions in comparison with continuous cropping systems fertilized with the full recommended P and K rates. In view of the global fertilizer crisis, this aspect is extremely relevant for agriculture in Brazil and around the world.

Methane emissions and milk yields from zebu cows under integrated systems

Integrated systems are technologies that potentially increase animal production and environmental preservation, but the effect of these systems on the efficiency and methane emissions of dairy cows is still unknown. This study aimed to compare enteric methane emissions, dry matter intake and performance of grazing dairy cows in integrated systems in the Brazilian Cerrado biome, i.e., crop-livestock integration (CLI) or crop-livestock-forest integration (CLFI). Eighteen Holstein-Zebu cows were randomly assigned to the two production systems (n = 9 for each system) based on Monbasa pasture (Megathyrsus maximus cv. Mombaça; Syn. Panicum maximum) under rotational stocking management. Herbage allowance ranged from 12 to 14% body weight, and cows were supplemented with concentrated feed according to milk yield. Herbage samples were collected by simulated grazing to determine nutritional value. Milk yield was determined weekly. Herbage intake was estimated from fecal output and indigestibility of the pasture dry matter. Fecal output was estimated by the external indicator LIPE®, and dry matter digestibility was estimated by the internal indicator NDFi. Enteric methane emissions were estimated by the SF6 tracer gas technique. Data were collected in three sampling periods to characterize the rainy season, the transition from the rainy season to the dry season and the dry season. Data were analyzed in split plots, with animals within the system as the plot and seasons as the subplot. Statistical significance was considered at P < 0.05. The herbage crude protein content was 35.9% higher on average in the CLFI than in the CLI. In vitro dry matter digestibility was 16.7% lower in the CLI than in the CLFI in the rainy season. Milk yield and feed efficiency were similar between systems and seasons. The total dry matter intake in the rainy season was 34.6% higher in the CLFI than in the CLI. The energy loss, production and yield of methane were 29.8%, 35.0% and 31.3%, respectively, lower in the rainy season than in the other seasons. Enteric methane emissions, milk yield and feed efficiency were similar between the integrated CLI and CLFI systems in the Brazilian Cerrado region.

Addressing the contribution of agricultural systems to the phosphorus pollution challenge: a multi-dimensional perspective

The intensification of agricultural systems has increased the food production efficiency, increasing the productivity while the production costs are reduced. Although these factors are key to global food security in a context of continued human population growth, the use of intensive agricultural techniques results in different environmental issues. Mitigating these negative impacts is a requirement for adopting sustainable food production systems. Notably, nutrient pollution is one of the main environmental issues associated with both livestock and crop production. These activities result in different point and non-point source releases of phosphorus, which eventually reach surface and ground waterbodies. This might result in the accumulation of phosphorus over time, contributing to the eutrophication of water ecosystems, and the development of harmful algal bloom (HABs) episodes. The releases of nutrients from agricultural activities can be abated through different management strategies, including the implementation of nutrient recovery techniques at livestock facilities, embracing precision fertilization methods, and developing integrated crop-livestock systems for achieving circular food production systems. In this work, we describe opportunities for Process System Engineering (PSE) to address the development of phosphorus management techniques for mitigating phosphorus pollution from agricultural systems balancing trade-offs between recovery cost and environmental impact mitigation. These techniques integrate the spatial analysis of nutrient pollution from agriculture using geographical information systems (GIS) with the assessment and the selection of phosphorus management techniques combining techno-economic analysis (TEA) and environmental metrics through multi-criteria decision analysis (MCDA) frameworks, and use mathematical programming for the conceptual design of integrated crop-livestock systems.

Nitrogen balance and efficiency as indicators for monitoring the proper use of fertilizers in agricultural and livestock systems

The rational use of nutrients is a key factor for the sustainability of agricultural systems. This study aimed to analyze the nitrogen balance and use efficiency, and the valorization of organic residues within integrated systems, in comparison to conventional agricultural and livestock systems. The experiment was assembled in a randomized blocks design with three replicates. Six production systems were compared, grain maize production (CROP) and pasture for beef cattle production (LS), and four ICLS (Integrated Crop-Livestock System) for grain maize and pastures for beef cattle, in 2 years. In order to estimate the nutrients balance, inputs, and outputs at farm levels were considered, and with the results obtained for nutrient balance, the use efficiency was calculated. The CROP presented higher nutrient use efficiency (1.43 kg/ha−1), but at the same time, it resulted in negative contributions for the nutrient balance (−97 kg/ha−1) because of lower amounts of nitrogen in the organic residues (188 kg/ha−1) and lower valuation. The LS and ICLS provided a higher amount of nitrogen (983 kg/ha−1; mean ± 921 kg/ha−1) and valuation of organic residues. The presence of components such as pastures and the animal contribute to a positive production system, while reducing the needs for chemical fertilizers.

Opportunities and challenges for the integration of sheep and crops in the Rio de la Plata region of South America

The Rio de la Plata region (Argentina, Uruguay, and southern Brazil) is currently characterized by a mosaic of intensively managed croplands and remaining areas of livestock production on native grasslands. The production of crops and animals in this scenario is usually spatially segregated as a result of mindset and structural constraints developed over decades of agricultural specialization. However, several studies have suggested that crop-livestock integration across various spatio-temporal scales can improve land-use efficiency and ecosystem services provisioning. In this context, the long-standing tradition of Rio de la Plata region’s ranchers on sheep production summed to the easy-to-manage body size of these small ruminants make them fit into a wide range of farm sizes and integrated crop-livestock system (ICLS) designs. In addition, the large variety of crops produced in the region, including annual (e.g., soybean, maize, rice and wheat) and perennial (e.g., orchards, vineyards and woodlands), and the diversity of temperate and tropical forage species used in livestock systems, provide multiple ICLS possibilities. In this review, we explore these possibilities and highlight the opportunities and challenges for integration of crop and sheep production in the Rio de la Plata region of South America. Using mainly data from the region’s ICLS, but also other parts of the world, we show that ICLS with sheep are able to improve nutrient cycling, land-use efficiency, and systems’ resilience and profitability if sound grazing intensities are used. Finally, we build on the idea of ICLS farm design to present an interactive, hands-on methodology recently developed to support farmers’ transition from specialized systems to ICLS.

Nitrous oxide and methane emissions affected by grazing and nitrogen fertilization in an integrated crop-livestock system

Attending the global demands for primary resources without jeopardizing the environment’s sustainability has become a challenge in recent decades. The adoption of conservationist systems, such as integrated crop-livestock systems (ICLs), has been widely discussed as a promising strategy. However, there is still scarce knowledge concerning pasture management, optimal fertilizer rates, and effects of livestock on soil processes, especially in the greenhouse gas emissions in subtropical climate regions. We aimed to assess soil nitrous oxide (N2O) and methane (CH4) emissions, crop yield, and nitrogen use efficiency (NUE) in an ICLs under grazing intensities and nitrogen (N) fertilization rates. A field experiment was conducted during the winter and summer crop seasons. In winter, black oat (Avena strigosa Schreb.) pasture was subject to grazing intensities: ungrazed, moderately grazed, and intensively grazed by heifers; and fertilized with different N rates: 0, 75, and 150 kg N ha−1. In the summer, soybean (Glycine max (L.) Merr.) was grown over those winter treatments. Soil N2O and CH4emissions were measured by the static chamber method, and the fluxes and cumulative emissions were calculated. Simultaneously, we measured the crops’ productivity and the NUE. Moderate grazing did not affect N2O and CH4 emissions relative to ungrazed but reduced the NUE in black oat. Conversely, intensive grazing combined with 75 and 150 kg N ha−1 increased soil N2O emissions, mainly during the winter. Grazing and N application did not change soil CH4 fluxes, characterized by CH4 uptake most of the time. Nitrogen fertilization, regardless of the rate, increased soil N2O emissions, but this fertilization and its residual effects were crucial to achieving high black oat and soybean yields. Results indicate that black oat can reach high yields in ICLs under moderate grazing and N fertilization rates of 75 and 150 kg N ha−1, with lower N2O emissions than under intensive grazing. Our study provided a quantitative assessment of an ICLs production efficiency in the Brazilian subtropics, regarding crop yield, NUE, and the emissions of important greenhouse gases to the atmosphere. The findings suggest that the use of moderate grazing with N fertilization on black oats may determine the trade-offs between food production and the harmful effects induced by land use.

Soil physical attributes in an integrated crop-livestock system with pasture managed under different sward canopy heights and different timings of nitrogen application

This study aimed to evaluate the physical attributes of soil in an integrated crop-livestock system with winter pastures managed under different N fertilization timings and canopy heights after winter and the soybean crop. The experimental design used was randomized blocks with the treatments in a 2 × 2 factorial arrangement (two canopy heights and two N application timings), with three area replications. The canopy heights were 11 and 24 cm kept by continuous stocking grazing method since May to November (175 days). Fertilization timings as N-pasture fertilization and N-corn fertilization (phase before the winter pasture). Treatments characterized as N fertilization inversion were applied with fertilization timings as N-pasture fertilization and N-corn fertilization (phase before the winter pasture). Soil density, total porosity, and moisture content were evaluated after winter pasture (black oat + annual ryegrass) and after the subsequent summer soybean crop. The sampling spots were georeferenced and analyzed using geostatistics, considering the position in the slope of landscape. Soil physical attributes were not influenced by canopy height nor N fertilization timing (P&gt;0.05). Soil density was reduced by 13.3% (from 1.11 to 0.98 g cm-3), whereas total porosity (from 0.58 to 0.62%) and moisture content (from 32.73 to 35.73%) increased by 6.9% and 9.2% after the soybean crop in relation to the values obtained in the winter pasture. The higher elevation areas had higher moisture content, total porosity, and lower density than the lower elevation areas, regardless of the time of evaluation. Well-drained soils were more resistant to compaction by animal trampling than moderately drained soils. In well-managed integrated crop-livestock systems in humid subtropical climate regions, the surface compaction of clayey soils in winter pastures is light, non-limiting, and disappears after the subsequent summer crop.

Diversified production systems in sandy soils of the Brazilian Cerrado: nutrient dynamics and soybean productivity

Increased functional diversity, given by the Integrated Crop-Livestock System (ICLS), is an alternative of quantitative and qualitative technical evolution for soybean (Glycine max) cropping in sandy soils. The objective of the present research was to investigate production systems with different levels of functional diversity in sandy soils of the Brazilian Cerrado regarding their (a) soil microbiological activity, (b) macronutrient accumulation and release, and (c) soybean yield. The experimental design was randomized blocks with three replications and the treatments corresponded to different levels of functional diversity: very low (Fallow), low (Ruziziensis), medium (Ruziziensis, niger, radish and rattlepod), and high (Ruziziensis, niger, radish and rattlepod with animal entrance). The plants were desiccated and the phytomass contained within a frame was collected at ground level. The evaluation of phytomass decomposition and nutrient release was performed at 0, 15, 30, 60, 90 and 120 days after desiccation (DAD) of the plants. Functional diversity levels increase the carbon content of the microbial biomass in the sandy soil, with an emphasis on systems with high plant diversity and the presence of animals. High functional diversity with the presence of the animal results in higher rates of phytomass decomposition and nutrient release with a shorter half-life (t 1/2=85 DAD), mainly with respect to potassium. This functional diversity increases soybean yield by up to 25% in the high diversity system compared to a system with very low diversity. The high functional diversity in ICLS enriches soil microbiological quality and increases soybean productivity in the sandy soil in the short term.

Estimating pasture aboveground biomass under an integrated crop-livestock system based on spectral and texture measures derived from UAV images

Pasture production under integrated crop-livestock systems (ICLS) is a key element to support grazing management decisions. Therefore, further experimentation is required to produce reliable estimates of pasture productivity. An unmanned aerial vehicle (UAV) is a viable tool to obtain fast and accurate aboveground biomass (AGB) estimates in pastures under ICLS. We tested several datasets of variables composed of original spectral bands (RGB-NIR), vegetation indices, and gray-level cooccurrence matrix (GLCM) textures to estimate pasture AGB using the random forest (RF) algorithm and feature selection methods in a commercial ICLS farm in western São Paulo State, Brazil. Field measures of pasture AGB were carried out in three field campaigns over five months to capture the spatiotemporal variability of the pasture fields. Most tested models reached similar results on pasture AGB estimates (R2: 0.60 to 0.70), while the number of variables selected for the RF algorithm differed among models (from 6 to 160 variables). The three more accurate models used few variables, two of which used only texture measures, while the third also employed combined spectral bands and vegetation indices. The best model (R2 = 0.70) used only 10 texture measures. Texture measures that represented images’ inner patterns, calculated from NIR, red-edge, and triangular greenness index data, were the most relevant variables for the main models. The texture contribution indicates important information to be considered to estimate pasture AGB when using UAV imagery. The results achieved by UAV estimates allow the design of multitemporal AGB pasture maps, which may be useful for building more reliable spatiotemporal data.

PROPRIEDADES FÍSICO-HÍDRICAS DE UM ARGISSOLO SOB PLANTIO DIRETO E INTEGRAÇÃO LAVOURA-PECUÁRIA NO CERRADO

ABSTRACT Light soils are more susceptible to degradation and need to be exploited in a conservational manner, thus avoiding rapid degradation. The objective of this study was to evaluate the physical-hydraulic properties of an Ultisol under no-tillage and crop-livestock integration in the Cerrado of eastern Maranhão state, Brazil. The evaluated managements were one area under no-tillage system for fourteen years (soybean/ millet) and three areas with different histories of adoption of the crop-livestock integration (CLI) system under no-tillage (soybean/millet), with the difference being: times of entry with CLI (2, 4 and 8 years), as well as a native Cerrado area, considered a control. Soil collection was carried out in June 2018 at depths of 0.00-0.10, 0.10-0.20, 0.20-0.30 and 0.30-0.50 m. Disturbed and undisturbed samples were collected to determine the following variables: bulk density, porosity, resistance to penetration, retention curve and available water capacity. Data were subjected to the calculation of means and confidence intervals (95%). The area with a recent history of crop-livestock integration showed better density, porosity, resistance to penetration, water storage capacity and available water. No-tillage for fourteen years leads to high resistance to penetration, less porosity and low water storage capacity. The integrated system (CLI) improves the quality of the physical- hydraulic properties and the values found are similar to those observed in an area under native vegetation.

EVALUATION OF EARLY SEASON MAPPING OF INTEGRATED CROP LIVESTOCK SYSTEMS USING SENTINEL-2 DATA

Abstract. Various approaches were developed considering the need to increase agricultural productivity in cultivated areas without more deforestation, such as the Integrated Crop livestock systems (ICLS). The ICLS could be composed of annual crops followed by pastureland with the presence of cattle. Due to the high temporal dynamic of rotation between crops over the season, monitoring these areas is a big challenge. Also, agricultural organizations worldwide highlight the need for early-season maps for this kind of work. In this context, this study evaluated the potential of open data (Sentinel-2) data to map ICLS areas. The performance of two classifiers was evaluated: one of Machine Learning (random forest) and the other of Deep Learning (LSTM). Three different time windows of data were tested (Entire season, 180 days, and 120 days). Using the RF classifier, it was possible to achieve satisfactory results (Overall accuracy higher than 80%) for the early season (180 days). However, further studies are needed to explain better the lower(when compared to Random Forest) accuracy achieved by LSTM net (0.79 % for 180 days) and compare the results achieved here with results for a study area with different rates of cloud cover.