Marcelo Valadares Galdos

Rothamsted Research · Sustainable Soils & Crops

The use of livestock waste as an organic fertiliser releases significant greenhouse gas emissions, exacerbating climate change. Innovative fertiliser management practices, such as treating slurry with plasma induction, have the potential to reduce losses of carbon and nitrogen to the environment. The existing research on the effectiveness of plasma...

The area of land dedicated to growing maize for bioenergy in the United Kingdom is rapidly expanding. To understand how maize production influences soil carbon (C) dynamics, and whether this is influenced by soil type, we measured net ecosystem exchange (NEE) using the eddy covariance technique over the 2021 growing season. We combined the NEE data...

Drought events have increased in frequency and severity in recent years, and result in significant economic losses. Although the Brazilian semi-arid northeast has been historically associated with the impacts of drought, drought is of national concern, from 2011–2019, drought events were recorded in all Brazilian territories. Droughts can have majo...

A mixed agricultural system that integrates livestock and cropping is essential to organic, agroecological, and regenerative farming. The demand for improved welfare systems has made the practice of outdoor rearing of pigs very popular; it currently makes up 40% of the UK pig industry and has also been integrated into arable rotations. Besides the...

Soil nitrous oxide (N2O) fluxes comprise a significant part of the greenhouse gas emissions of agricultural products but are spatially and temporally variable, due to complex interactions between climate, soil and management variables. This study aimed to identify the main factors that affect N2O emissions under sugarcane, using a multi-site databa...

Recently, many countries have introduced policies that promote sustainable agricultural practices, such as reducing synthetic nitrogen fertiliser and promoting diversified crop rotation. While such management changes might represent an opportunity for the agricultural sector to mitigate the impacts of climate change through carbon (C) sequestration...

Grasslands are the largest contributor of nitrous oxide (N 2 O) emissions in the agriculture sector due to livestock excreta and nitrogen fertilizers applied to the soil. Nitrification inhibitors (NIs) added to N input have reduced N 2 O emissions, but can show a range of efficiencies depending on climate, soil, and management conditions. A meta-an...

The rice-maize (R-M) system is rapidly expanding in Bangladesh due to its greater suitability for diverse soil types and environments. The present conventional method of cultivating puddled transplanted rice and maize is input-intensive, decreases soil health through intense ploughing, and ultimately reduces farm profitability. There is a need to i...

The EAT–Lancet Commission devised a sustainable reference diet with the aim of reducing the incidence of non-communicable diseases and mortality globally while improving food system sustainability. The extent to which the reference diet supports cognitive function across the life course, however, has not yet been evaluated. This Review assesses the...

Bioenergy from sugarcane production is considered a key mitigation strategy for global warming. Improving its representation in land surface models is important to further understand the interactions between climate and bioenergy production, supporting accurate climate projections and decision‐making. This study aimed to calibrate and evaluate the...

Climate change will put millions more people in Africa at risk of food and nutrition insecurity by 2050. Integrated assessments of food systems tend to be limited by either heavy reliance on models or a lack of information on food and nutrition security. Accordingly, we developed a novel integrated assessment framework that combines models with in-...

Eucalypt is one of the most-planted broadleaf genera around the globe, exhibiting high yield, plasticity and growing capacity on a broad range of environments. The main objective of this study is to present the integration of a specific module for eucalypt short-rotation plantations into ECOSMOS (Ecosystem Model Simulator). Different calibrations a...

Maize (Zea mays L.) is a prominent Brazilian commodity, being the second largest crop produced and fifth exported product by the country. Due to its importance for the agricultural sector, there is a concern about the effect of climate change on the crop. Process‐based models are valuable tools to evaluate the effects of climate on crop yields. The...

We identify major knowledge gaps in the primary impacts of extreme weather and climate change across the UK’s food system, its functioning and their interactions to provide information to support adaptation and resilience planning. Future shocks and stresses due to changes in weather and climate extremes will have significant impacts on the UK food...

Crop modeling is affected by parameter uncertainty. We proposed a framework that integrates sensitivity, uncertainty and parameter calibration of crop models, to provide prediction intervals in place of single values for decision-makers to reduce management risks in agriculture. The framework includes four steps: (1) set prior distributions of para...

The semiarid lands of Northeast Brazil represent one of the most densely populated regions of the country. Rainfall variability together with land degradation and large-scale poverty in rural areas makes this region vulnerable to droughts. Most of the agriculture in this region is rainfed and deficient rainfall leads to severe drought impacts. In t...

Soil moisture information is essential to monitoring of the intensity of droughts, the start of the rainy season, planting dates and early warnings of yield losses. We assess spatial and temporal trends of drought over the Brazilian semiarid region by combining soil moisture observations from 360 stations, root zone soil moisture from a leading lan...

East Africa is highly reliant on agriculture and has high rates of soil erosion which negatively impact agricultural yields. Climate projections suggest that rainfall intensity will increase in East Africa, which is likely to increase soil erosion. Soil erosion estimates require information on rainfall erosivity, which is calculated using sub-daily...

Over the last three decades, few studies have been conducted to tackle the complexity and heterogeneity of Bangladesh farming systems. We address these research gaps with a new survey. Accordingly, a survey was conducted in North‐Western Bangladesh to understand how socio‐economic traits influence technology adoption and to identify and characteriz...

Smallholder farmers in sub‐Saharan Africa (SSA) currently grow rainfed maize with limited inputs including fertilizer. Climate change may exacerbate current production constraints. Crop models can help quantify the potential impact of climate change on maize yields, but a comprehensive multi‐model assessment of simulation accuracy and uncertainty i...

Leaching of nitrate from fertilisers diminishes nitrogen use efficiency (the portion of nitrogen used by a plant) and is a major source of agricultural pollution. To improve nitrogen capture, grasses such as brachiaria are increasingly used, especially in South America and Africa, as a cover crop, either via intercropping or in rotation. However, t...

Nitrous oxide (N2O) emissions from soils comprise a significant part of the carbon footprint of agricultural products, but are highly spatially and temporally variable. Sugarcane, an important source of ethanol, sugar and electricity, has emission factors (EF) ranging from 0.04 to 3% of N applied, depending on management and environmental condition...

Livestock production has high impact in the environment, contributing up to 18% of total anthropogenic greenhouse gases emissions (GHG), around 80% of the agriculture sector. Enteric methane (CH4) from ruminants and nitrous oxide (N2O) from manure deposited in pastureland are the main sources. The aim of this study was to evaluate the global potent...

Carbon and water budgets of forest plantations are spatially and temporally variable and hardly empirically predictable. We applied G'DAY, a process-based ecophysiological model, to simulate carbon and water budgets and stem biomass production of Eucalyptus plantations in São Paulo State, Brazil. Our main objective was to assess the drivers of spat...

Zero-tillage (ZT) is being increasingly adopted globally as a conservationist management system due to the environmental and agronomic benefits it provides. However, there remains little information on the tillage effect on soil pore characteristics such as shape, size and distribution, which in turn affect soil physical, chemical and biological pr...

The aviation industry is committed to reducing its environmental impact and has established ambitious goals to decrease CO2 emissions by 50% by to 2050. The replacement of fossil fuels by jet-biofuels is one of the main strategies to attain the emission targets. Therefore, the aim of this study was to provide a detailed survey on land availability...

Soil organic carbon (SOC) change influences the life-cycle assessment (LCA) calculations for globally traded bio-based products. Broad agreement on the importance of SOC measurement stands in contrast with inconsistent measurement methods. This paper focuses on published SOC research on lands managed for maize (Zea mays L.) in the U.S. and sugarcan...

Sugarcane-derived ethanol from Brazil has a high output to input energy ratio and high greenhouse gas savings compared to fossil fuels. Current ethanol production is based on first generation (1G) technology, which ferments the sugars extracted from sugarcane stalks. Cellulosic ethanol (2G) can be produced from what is currently considered agricult...

Despite the significant inroads into increasing agricultural productivity in recent decades, nitrogen remains a key limiting factor for crop growth and yield. Though highly variable globally, the amount of reactive N added yearly onto cropland that is subsequently lost to the environment remains high. As such the interest in agronomic approaches to...

Ethanol production in Brazil poses many challenges. This is due to the fact that there are new players in the business, the expansion will mostly occur in less traditional areas, improving sustainability is mandatory, and the industry needs to move toward production diversification and the development of second-generation biofuels. This chapter ana...

Rapid expansion in biomass production for biofuels and bioenergy in the Americas is increasing demand on the ecosystem resources required to sustain soil and site productivity. We review the current state of knowledge and highlight gaps in research on biogeochemical processes and ecosystem sustainability related to biomass production. Biomass produ...

Currently, Brazilian sugarcane monitoring is done by official agencies (Brazilian Institute of Geography and Statistics (IBGE), Ministry of Agriculture (MAPA), National Supply Company (Conab)) through agricultural statistics. As sugarcane is produced in large areas in Brazil, it is evident the need of creating new mapping methods especially new met...

Currently, Brazilian sugarcane monitoring is done by official agencies (Brazilian Institute of Geography and Statistics (IBGE), Ministry of Agriculture (MAPA), National Supply Company (Conab)) through agricultural statistics. As sugarcane is produced in large areas in Brazil, it is evident the need of creating new mapping methods especially new met...

The production and use of biofuels has increased rapidly in recent decades. Bioethanol derived from sugarcane has become a promising alternative to fossil fuel for use in automotive vehicles. The “savings” calculated from the carbon footprint of this energy source still generates many questions related to nitrous oxide (N2O) emissions from sugarcan...

The effects of land-use change (LUC) on soil carbon (C) balance has to be taken into account in calculating the CO2 savings attributed to bioenergy crops1, 2, 3. There have been few direct field measurements that quantify the effects of LUC on soil C for the most common land-use transitions into sugar cane in Brazil, the world’s largest producer 1,...

The development of cellulosic feedstocks for biofuels and other bioproducts must be accomplished in an economically viable, environmentally benign, and socially sustainable manner. This task is feasible throughout the world, as illustrated in this chapter. The chapter discusses production of cellulosic ethanol in Brazil, cellulosic bioenergy in Chi...

Sugarcane ethanol has been produced in Brazil since the early 20th century, but production increased in the mid-1970s aiming at substituting 20% of the gasoline. Despite an increase in the 2000s production has been stable since 2008. This paper presents a review of the main developments achieved and future challenges. The sector has had positive ec...

In 1975 the Brazilian Government launched the National Alcohol Program aiming to partially replace the oil imported by national energy sources. For many reasons, sugarcane became nearly the exclusive feedstock source for bioethanol production (Rosillo-Calle and Cortez, 1998). According to Rudorff et al. (2010) the São Paulo's sugarcane area increas...

Plant biomass has been recognized globally as an important link to a sustainable energy future because it can be grown universally and converted into liquid transportation fuels or other material through biochemical, thermochemical, or catalytic conversion processes. However, those potential benefits must be viewed in the context of other global so...

Large scale expansion of sugarcane production in Brazil is very positive in terms of biofuels and greenhouse gases; however, potential impacts on water resources are uncertain. The objective of this analysis is to assess potential impacts of biofuel expansion in Central South Brazil on water resources using the South American Land Data Assimilation...

Strategies to mitigate climate change through the use of biofuels (such as ethanol) are associated not only to the increase in the amount of C stored in soils but also to the re-duction of GHG emissions to the atmosphere.This report mainly aimed to propose appropriate methodologies for the determinations of soil organic carbon stocks and greenhouse...

Mechanized sugarcane (Saccharum spp.) harvest without burning has been increas-ingly adopted in Brazil, increasing trash availability on the fi eld. This study aims at showing the importance of using an integrated framework tool to assess technical and economic impacts of integral harvesting and baling trash recovery strategies and different recove...

Sugarcane produced in Brazil has several environmental advantages. However, burning residues, which leads to GHG and black carbon (BC) emissions, has been used to facilitate manual harvest. BC emissions have a net warming effect and cause health problems. Mechanized harvest without burning is gradually replacing manually harvested burned sugarcane....

Curerntly, the development of second generation ethanol has been intensely researched in Brazil. That has generated a demand for identifying the areas with the highest potential for straw production on which to base second generation ethanol plants. This work described the production of straw production maps for the microregion of Ribeirão Preto, S...

The Brazilian Amazon and Cerrado are among the principal agricultural frontiers of the world, and have attracted global attention because of their potential to be a source or sink of atmospheric CO2. However, accurately quantifying alterations in soil organic carbon (SOC) due to land-use changes remains to be a major challenge. Using a meta-analysi...

American Geophysical Union Fall Meeting 3-7 December 2012 Increasing crop water productivity is a key factor where water is scarce compared with land and other resources. A widespread method for water use assessment is the water productivity (WP) approach which is the ratio between biomass production per unit of water utilized. WP is useful to eval...

Increasing crop water productivity is a key factor where water is scarce compared with land and other resources. A widespread method for water use assessment is the water productivity (WP) approach which is the ratio between biomass production per unit of water utilized. WP is useful to evaluate water utilization and to identify where and when wate...

One of the controversial aspects of adopting biofuels as a global warming mitigation strategy is the land use change (LUC) due to the expansion of feedstock production. Thus, the LUC due to the sugarcane expansion in Brazil in 1996-2012 was evaluated, using national statistics and remote sensing data. In this period, soybean was the major crop rega...

Brazil is the country estimated to have the largest supply of freshwater in the world. The Brazilian river system is comprised of navigable rivers and waterways generated by river segments, besides large isolated lakes, created by dams constructed exclusively for electricity generation. Moreover, the country has high humidity conditions in most of...

Agricultural management practices that promote net carbon (C) accumulation in the soil have been considered as an important potential mitigation option to combat global warming. The change in the sugarcane harvesting system, to one which incorporates C into the soil from crop residues, is the focus of this work. The main objective was to assess and...

In this paper, Least-Square Support Vector Machine (LS-SVM) regression is used to for a rapid and accurate quantification of total carbon (total-C) and total nitrogen (total-N) in soil samples collected in forest and sugarcane areas in Sao Paulo State, Brazil. NIRS spectra were recorded on a NIRS 5000 scanning monochromator. The concentration range...

Biofuels are both a promising solution to global warming mitigation and a potential contributor to the problem. Several life cycle assessments of bioethanol have been conducted to address these questions. We performed a synthesis of the available data on Brazilian ethanol production focusing on greenhouse gas (GHG) emissions and carbon (C) sinks in...

National inventories of anthropogenic greenhouse gas (GHG) emissions (implementation of the National Communications) are organized according to five main sectors, namely: Energy, Industrial Processes, Agriculture, Land-Use Change and Forestry (LUCF) and Waste. The objective of this study was to review and calculate the potential of greenhouse gas m...

Burning sugarcane leaves and tops on standing mature crops has been practiced for centuries in Brazil, in order to facilitate the harvest, transportation and processing of sugarcane stalks. Currently, due to economic, environmental and legal reasons, the unburned harvest, with residues left on the soil, has been increasingly adopted. There is littl...

Data from the 1990-1994 period presented in the "Brazil's Initial National Communication" document indicated that the country is one of the top world greenhouse gas (GHG) emitters. A large majority of Brazil's GHG emissions come from deforestation mainly of the Amazon biome for agriculture and livestock land uses. This unique inventory is now out o...

Soil bulk density values are needed to convert organic carbon content to mass of organic carbon per unit area. However, field sampling and measurement of soil bulk density are labour-intensive, costly and tedious. Near-infrared reflectance spectroscopy (NIRS) is a physically non-destructive, rapid, reproducible and low-cost method that characterize...