The nitrogen is a macronutrient essential for the functioning of the metabolism of living beings. However, due to the changes that the planet has been passing in the Anthropocene, the nitrogen cycling has been altered. Deforestation combined with changes in land use are primarily responsible for the change in their cycling. Emissions of greenhouse gases such as N2O were increased due to this deforestation and inadequate soil management practices, and this contributed to the fact that these changes in nitrogen cycling occurred. Considering the importance of nitrogen and the changes that it has undergone in the last decades, this work of revision aims to describe the role of nitrogen and the changes in its cycling due to the processes of land use change that occurred in the Anthropocene in forest areas tropical and eucalyptus plantations in Brazil.

Brazil has always maintained a prominent position in negotiations within the United Nations Framework Convention on Climate Change, playing a major role in setting increasingly ambitious goals and encouraging consensus among Parties. With the purpose of reducing GHG emissions from the agricultural sector and disseminating and financing good agricultural practices, Brazil developed a platform of sustainable technologies and public policies, as the Low Carbon Agriculture Plan (the “ABC Plan”). This article reviews the main milestones of Brazil’s role in the international negotiation on climate change, how these factors affected the Brazilian agricultural sector between 2009 and 2018 and the authors’ personal view on this context. The objective is to provide an overview of Brazil’s actions regarding the agricultural sector which contribute to the voluntary commitment assumed by the Brazilian government at COPs 15 and 21 and to provide a critical analysis of how these actions are being implemented. The main results show that low carbon agriculture has been consolidated as the main Brazilian strategy for sustainable rural development, but it is vital for our country to continue with these actions.

Abstract: Nitrogen is the most abundant element of the atmosphere, being present in the constitution of several atmospheric gases, among them nitrous oxide (N2O). The N2O is one of the most powerful greenhouse gases, due to its high potential for global warming. In Brazil, the sector that emits more N2O to the atmosphere is Agriculture, due to the high amounts of nitrogen fertilizers applied in the field. However, the country has an advanced public policy of adopting agricultural technologies that contribute to the reduction of this problem. The present review aims to show the dynamics of Nitrogen in agricultural and forest systems, the role of Nitrogen in the economy and present the main mitigation strategies in greenhouse gas emissions in agriculture.

ABSTRACT – This study aimed to evaluate the frequency and intensity of GreenFeed (GF) use by Nellore steers using different attractants in pastures of integrated systems. The attractant protein supplement and Tifton bermudagrass pelleted hay flavored with vanilla were evaluated over a period of 15 days. The pelleted hay stimulated the animals to stay longer in the equipment (24.23 s), with 8% more visits in intervals longer than 30 s in contrast to protein supplement. This indicates that pelleted hay flavored with vanilla is a potential attractant to encourage Nellore steers to visit GF in grazing systems.

The increase of greenhouse gases in the atmosphere raises the average temperature of the planet, triggering problems that threaten the survival of humans. Protecting the global climate from the effects of climate change is an essential condition for sustaining life. For this reason, governments, scientists, and society are joining forces to propose better solutions that could well-rounded environmentally, social and economic development relationships. International climate change negotiations involve many countries in establishing strategies to mitigate the problem. Therefore, understanding international negotiation processes and how ratified agreements impact a country is of fundamental importance. The purpose of this paper is to systematize information about how climate negotiations have progressed, detailing key moments and results, analyzing the role that Brazil played in the course of these negotiations and the country’s future perspectives.

Several studies indicate that the use of integrated production systems, such as integrated crop-livestock-forest systems (ICLF), improves the quality of the soil and consequently the sequestration of organic carbon in the soil. In this way, this work aims to evaluate the carbon stocks in soil under different management systems in the Cerrado/Amazonia transition zone, namely: ICLF, no-tillage, pasture and eucalyptus plantation. For this, two soil sam- plings were done in 2011 and 2014, in the 0 – 5, 5 – 10 and 10 – 30 cm layers. Soil carbon and nitrogen stocks were analyzed. ICLF system was the treatment that obtained the highest percentage of carbon gain (7.8%) after three years of establishment which represents to an increase of 5.5 Mg·ha−1. Management systems, such as ICLF, with minimal soil disturbance combined with crop ro- tations that contribute to the quantity and quality of residues input, increase soil organic matter content. Carbon stock data show the potential of ICLF systems to increase soil carbon stocks.

Until 2019, the Brazilian federal government employed a number of policy measures to fulfill the pledge of reducing greenhouse gas emissions from land use change and agriculture. While its forest law enforcement strategy was partially successful in combating illegal deforestation, the effectiveness of positive incentive mea- sures in agriculture has been less clear. The reason is that emissions reduction from market-based incentives such as the Brazilian Low-Carbon Agriculture Plan cannot be easily verified with current remote sensing monitoring approaches. Farmers have adopted a large variety of integrated land-use systems of crop, livestock and forestry with highly diverse per-hectare carbon balances. Their responses to policy incentives were largely driven by cost and benefit considerations at the farm level and not necessarily aligned with federal environmental objectives. This article analyzes climate-related land-use policies in the state of Mato Grosso, where highly mechanized soybean–cotton and soybean–maize cropping systems prevail. We employ agent-based bioeconomic simulation together with life-cycle assessment to explicitly capture the heterogeneity of farm-level costs, benefits of adoption, and greenhouse gas emissions. Our analysis confirms previous assessments but suggests a smaller farmer policy response when measured as increase in area of integrated systems. In terms of net carbon balances, our simulation results indicate that mitigation effects at the farm level depended heavily on the exact type of livestock and grazing system. The available data were insufficient to rule out even adverse effects. The Brazilian experience thus offers lessons for other land-rich countries that build their climate mitigation policies on eco- nomic incentives in agriculture.

The application of liquid pig slurry (LPS) to pastures offers potential as a fertilizer but could have a direct influence on soil CO2 emissions. This study evaluated soil carbon dioxide emissions after successive LPS applications to soils under pasture cultivation. The experiment was carried out on ‘Tifton-85’ bermudagrass pasture cultivated in a red-yellow oxisol soil in the municipality of Lucas do Rio Verde-MT, Brazil. Two treatments were evaluated: the control and an application of 20 m3 ha-1 of LPS after each cut of the pasture. The CO2 emissions from the soil were determined using a high-precision infrared gas analyzer. Soil temperature and soil moisture were determined as were micrometeorological variables. The application of LPS had a significant effect on soil C-CO2 flow. The average flow of C-CO2 from the soil for the control treatment and with the application of LPS was 0.236 g C-CO2 m-2 h-1 and 0.291 g C-CO2 m-2 h-1, respectively. The application of LPS increased the accumulated CO2 emissions from the soil by 23.2%. Soil temperature and moisture are the main factors regulating the process of soil CO2 emission. These factors therefore need to be considered when evaluating the impact of LPS application on greenhouse gas emissions.

Abstract

Soils have important roles in the global budgets of the greenhouse gases. The liquid pig slurry (LPS) in pastures has high potential as a fertilizer but could have a direct influence on emission of greenhouse gasses. This study evaluated the effects of the application of LPS and inorganic mineral fertilization during the rainy and dry seasons on the emissions of CO2, CH4 and N2O in pastures planted with Tifton-85. The following treatments were tested: Control – no fertilization; LPS30 – 30 m3 ha-1; LPS60 – 60 m3 ha-1; LPS90 – 90 m3 ha-1 and inorganic mineral fertilization. Gasses were sampled using static chambers first during the months of March and April, then in June and July. Fertilization with LPS caused an increase in the flux of CO2 and CH4 during the first hours after its application, and CO2 emissions are greater during the rainy than in the dry season. However, the application of LPS in Tifton-85 pasture during rainy periods did not show high potential for emission of CO2, in contrast to application during the dry season. Fertilization with LPS increases the emission of N2O, and this varies as a function of the volume of LPS applied and the experimental conditions experimental conditions. The application of LPS in Tifton-85 pasture has a high potential for N2O emission during the rainy season, but the magnitude is similar to that resulting from inorganic mineral fertilization.