Mixed crop–livestock long-term experiments (LTE) are critical to increase the understanding of sustainability in complex agroecosystems. One example is the ‘Palo a Pique’ LTE which has been running for 25 years in Uruguay (from 1995 to present), evaluating four pasture–crop rotations under livestock grazing with no-till technology in soils with severe limitations. The results demonstrate that cropping systems reduced soil organic carbon (SOC) compared with permanent pastures, and that perennial pastures rotating with crops were critical to mitigate SOC losses. Data from the ‘Palo a Pique’ LTE has contributed to the establishment of new national policies to secure the sustainability of agricultural-based systems. Although the original purpose of the LTE was oriented to crops and soils, a demand for sustainable livestock intensification has gathered momentum over recent years. As a result, the current approach of the ‘Palo a Pique’ LTE matches each pasture–crop rotation with the most suitable livestock strategy with the common goal of producing 400 kg liveweight/ha per year. General approaches to the pursuit of sustainable livestock intensification include shortening the cycle of production, diversifying animal categories, increasing liveweight gain and final animal liveweight, and strategic livestock supplementation. Prediction of trade-offs between environmental, economic, and production indicators can be addressed through monitoring and modeling, enabling the timely anticipation of adverse sustainability issues on commercial farms. The ‘Palo a Pique’ LTE serves as a framework to address contemporary and future questions dealing with the role of ruminants on climate change, competition for land, nutrient dynamics, and food security.

Rice (Oryza sativa L.) systems rotated with perennial pastures have intensified in South America to increase annual grain productivity, but the effects on rice yield and soil quality remain poorly understood. We evaluated rice grain yield, crop and pasture biomass production, and soil organic carbon (SOC) and total nitrogen stocks (0–15‐cm depth) in three rice‐based rotations over 8 yr in Uruguay. Treatments were: (a) rice–pasture [a 5 yr rotation of rice–ryegrass (Lolium multiflorum Lam.)–rice, then 3.5 yr of a perennial mixture of tall fescue (Festuca arundinacea Schreb.), white clover (Trifolium repens L.), and birdsfoot trefoil (Lotus corniculatus L.)], (b) rice–soybean [a 2‐yr rotation of rice–ryegrass–soybean (Glycine max [L.] Merr.)–Egyptian clover (Trifolium alexandrinum L.)], and (c) rice–cover crop (an annual rotation of rice–Egyptian clover). Rice after soybean or pasture achieved the highest yield (9.8 Mg ha^–1), 9% higher than rice after rice in the rice–pasture and rice–cover crop systems. Estimated belowground biomass under rice–pasture (2.7 Mg ha^–1) was 12 and 42% greater than under rice–cover crop and rice–soybean rotations, respectively. Rice–pasture showed an increase of 0.6 Mg ha^–1 yr^–1 of SOC; no changes were observed in the intensified rotations replacing pasture with additional rice or soybean. All systems sustained soil total N. These results provide insights for implementing sustainable rice‐based rotations, with rice–pasture being the only system that increased SOC while achieving high rice yields and belowground biomass productivity.

Integrated Crop Livestock Systems (ICLSs) use productive diversification as a strategy to improve productivity and land use efficiency. Pasture Crop Rotations are a part of ICLSs and imply a pasture phase included in the sequence of crops. The main reasons to include pastures in crop systems are low productivity of natural grasslands and increased crop yield after a pasture phase. Our objective was to analyze the productivity indicators and management of four ICLSs that combine crop and livestock production, with data collected over a 3 y period (2019–2022). The experimental site was The Palo a Pique (Treinta y Tres, Uruguay) long-term experiment installed in 1995, located in the subtropical climate zone and on Oxyaquic Argiudolls soils (3% average slope). Systems evaluated were CC (continuous cropping), SR (two years idem CC, two years of pastures), LR (two years idem CC, four years of pastures) and FR (continuous pasture with Tall Fescue). Liveweight (LW) production, grain production and dry matter (DM) production were evaluated. Liveweight production was higher in CC and SR (426 and 418 kg LW/ha) than in LR (369 kg LW/ha) and FR (310 kg LW/ha). DM production was higher in FR and SR (6867 and 5763 kg DM/ha/year) than in LR (5399 kg DM/ha/year) and CC (5206 kg DM/ha/year). Grain production was 10%, 16% and 9% lower in soybean, wheat and sorghum in CC.

Paspalum L. is a genus of the Poaceae family, with many species serving as well-adapted forage plants in subtropical climates and continuous grazing systems. However, Claviceps paspali, an ascomycete of the order Hypocreales, represents a major threat to the Paspalum species. This fungus induces ergot disease, characterized by the replacement of infected flower seeds with sclerotia, which adversely affects seed production and animal health through mycotoxin production. Although ergot disease is reported in many countries, no totally resistant Paspalum cultivars have been reported for commercial use. This study comparatively evaluated disease development in six Paspalum species under greenhouse conditions with three specific isolates of C. paspali, along with field trials. In addition, field isolates of C. paspali were analyzed for phenotypic characteristics and phylogenetic relationships. Greenhouse evaluation revealed variable susceptibility among Paspalum species, with P. malacophyllum, P. notatum, and P. umbrosum being the most resistant. In field trials P. dilatatum showed the highest severity index, and P. umbrosum and P. malacophyllum were less affected. The phenotypic characterization of 22 C. paspali isolates showed variability in pigmentation and growth rates, with potato dextrose agar being the culture medium in which the highest growth rate was observed. Phylogenetic analysis of the isolates identified two well-supported lineages between C. paspali species. This research reports an ergot resistance gradient among Paspalum species, identifying genuine sources of resistance. In addition, virulent isolates of C. paspali potentially useful for rapid screening of accessions or crosses in Paspalum breeding programs were identified. [ ] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Sustainable intensification (SI) of production systems aims to increase yields without compromising the health of ecosystems. Integrated crop-livestock systems have been proposed as an SI alternative. Crop-pasture rotations are part of these systems and involve a pasture phase included in the crop sequence. The main reasons for including pastures in cropping systems are the low productivity of natural pastures and the increased crop yields after a pasture phase. The objective was to evaluate multidimensionally alternatives for intensifying crop-livestock systems for the period from May 2019 to April 2022, using information obtained from the long-term Palo a Pique experiment by INIA Treinta y Tres. The evaluated systems were CC (continuous cropping), SR (two years of CC, two years of pastures), LR (two years of CC, four years of pastures) and FR (continuous pasture with fescue). Live weight (LW) production was higher in CC and SR (426 and 418 kg LW/ha) than in LR (369 kg LW/ha) and FR (310 kg LW/ha). Grain production was 10%, 16% and 9% lower in soybean, wheat and sorghum in CC. The greenhouse gas (GHG) emission estimates were 11.3, 11.8, 11.8 and 16.4 kg CO2-eq/kg of LW produced for CC, SR, LR and FR. The average emissions of crops were 1.23, 0.53 and 0.52 kg CO2-eq/kg for soybean, wheat and oat. The NUE of the system was 43.4%, 28.1%, 29.3% and 5.5% for CC, SR, LR and FR. The N balance at the system level was 4.9±1.52, 41±3.1, 29±2.2 and 64±3.5 for CC, SR, LR and FR. On average, the gross margin was 285, 200, 181 and 197 US$/ha for LR, SR, CC and FR. Crop-livestock systems with a pasture phase (short or long) in the rotation can improve various sustainability indicators.