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Climate Change in Grassland Ecosystems
Published in Brenda Groskinsky, Climate Actions, 2022
Jesse Nippert, Seton Bachle, Rachel Keen, Emily Wedel
For these reasons, climate change is likely to threaten global food security. However, modern agriculture could potentially be further facilitating changes in climate (Tilman et al. 2011), particularly through increased methane emissions and disruption of natural nitrogen cycling. In addition, high-yielding lands for sustainable agriculture are no longer available, and yet the future demand for larger amounts of food in the context of an uncertain climate is increasing. Future efforts must focus on novel methods of sustainable agriculture that can produce higher yields from existing agricultural land, reduce chemical inputs leading to reductions in soil quality or environmental contamination and reduce food waste and the disparity in food security that exists across nations and regions.
Ecosystems: Diversity
Published in Yeqiao Wang, Terrestrial Ecosystems and Biodiversity, 2020
Agroecosystems are managed ecosystems designed for the production of crops and livestock. Conventional agroecosystems have lower species diversity, a more homogenous ecological structure, and modified growth dynamics and agricultural input. To overcome the climatic and soil constraints, the productivity of agroecosystems can be enhanced through the use of machinery and human practices such as irrigation and the application of fertilizers, pesticides, herbicides, and fungicides. Arable fields are composed of crop species that are cultivated for biomass harvest and usually have a short life-cycle and small size; weeds, which are unwanted species that compete with the crops for sunlight, space, water, and nutrients; and pests such as insects that cause harm to crops in terms of health and productivity. The organic matter turnover and nutrient cycling of agricultural fields is manipulated. Biodiversity can be remarkably low in monocultures, in contrast with the general relationship between biodiversity, productivity, and ecological stability. Agricultural systems can be classified according to farming intensity, the degree of mechanization and the use of agrochemicals. Industrial farming is a conventional system, while integrated and organic farming use less or no pesticides and chemical fertilizers. The majority of agricultural land is formed by the conversion of forests. In addition to food production, agricultural land provides ecosystem services such as organic recycling, carbon sequestration, and landscape attributes.
Introduction
Published in Yasmina Bestaoui Sebbane, Intelligent Autonomy of Uavs, 2018
Soil monitoring is important for maximizing crop yields. Accurate and up-to-date maps of water status, nutrient deficiencies and pest infestation allow farmers to take rapid, targeted action that minimizes costs and environmental impact. Manual monitoring involves taking ground samples and estimating the soil water status at random locations. For large areas, this is time consuming and cost intensive; furthermore, it gives only a sparse sampling of the area. Advances in imaging and computation have also made spectral imaging techniques more affordable. By combining these technologies, remote sensing techniques can now be economically applied to make frequent and high resolution surveys of agricultural land. UAS-based spectral imaging (SI) acquires spatially resolved images of a measurement sample at different wavelengths and combines them into a 3-D image cube. The two classical approaches for the acquisition of hyper-spectral image data are wavelength scanning and spatial scanning. Both methods have in common that it takes more than one integration time for the acquisition of a hyper-spectral image cube. The image sequence was stitched together and the normalized difference vegetation index (NDVI) was calculated and used to classify each pixel in the image [35].
Integrating water, sediments, and land use analysis for pollution assessment in a countryside urban-farming watershed landscape in southern Brazil
Published in International Journal of River Basin Management, 2022
Luciane Vieira, Leonardo Antunes Pessoa, Vinícius Estevan Carvalho Pereira, Karen Silvério Gois, Edivando Vitor do Couto
The forest shrinkage, especially around the streams, causes significant damage to water quality and biodiversity (Tabacchi et al., 2000). The integrity of riparian forests is of paramount importance for the preservation of watersheds. In addition to protecting the soil from erosion and loss of biota and microbiota, it acts as a natural physical barrier, limiting runoff of soil and pesticides reaching the water body. By limiting runoff, forests also prevent water and soil contamination from rivers and springs (Xu et al., 2020b). The results of CRW land use reinforce the potential of different sources of metals present in the sediment. Highlight the respective divisions of the activities developed in the surroundings and the percentage of the area used for each activity (Xu et al. 2020a). Land-use change impacts ecosystems’ status, integrity, and capacity to supply ecosystem services (Bormann et al., 2012; Daily et al., 2009; Nelson et al., 2009; Conceição et al., 2022). There is consensus that agricultural land uses, in particular, can bring negative impacts on ecosystem services or ‘ecosystem disservice’ (Dale & Polasky, 2007; Zhang et al., 2007) as the agricultural land uses intend to increase yield and production for maximizing economic return while undermining other ecosystem services, and thus resulting into ecosystem liabilities.
Role of land use and land cover in residential exposures to agricultural pesticide models
Published in International Journal of Environmental Health Research, 2022
Clémence Vannier, Cécile Chevrier, Laurence Hubert-Moy
Remote sensing is also frequently used to monitor agricultural land use, such as crops and grasslands, from national to local scales (Duveiller and Defourny 2010; Hansen and Loveland 2012; Atzberger 2013; Esch et al. 2014; Inglada et al. 2017; Gao et al. 2017; Waldhoff et al. 2017; Lasseur et al. 2018). Very high temporal resolution data such as MODIS, Landsat, and Sentinel-2 are commonly used and can be merged with high or other very high spatial resolution data to combine advantages of each dataset (Lasseur et al. 2018). Time series are usually used to define crop phenology and intensity precisely to follow crop succession over several years or to produce maps with a precise typology using decision trees or specific multi-temporal classifiers (e.g. support-vector machine, random forest) (Inglada et al. 2017; Gao et al. 2017; Lasseur et al. 2018). Currently, online tools provide free data and software that can be used to create personalised LULC maps for the present and past (Shelestov et al. 2017; Murray et al. 2018; Faure et al. 2018b). The free data and tools are useful for characterising and mapping crops and grasslands precisely in rural landscapes, and thus for more precisely considering pesticide sources and broad mitigation elements (e.g. woods, riparian zones, bushes).
The spatial distribution and determinants of irrigators’ price choices for water entitlement trading
Published in Australasian Journal of Water Resources, 2022
The further away irrigators were located to cities with a population over 5,000 people,5 the higher their price choices for buying water entitlements (until a certain distance point, reflected by the significant squared term of this variable). This may also reflect lower resource areas or lower connection to infrastructure. As previously, irrigators who remained in irrigated agriculture throughout the Millennium Drought and in rural areas may have made substantial farm investments and are therefore likely to pay more for water. Also, a higher socio-economic index of the irrigator’s region is associated with higher water entitlement selling prices. This reflects a potential higher agricultural production value and higher agricultural land values in those regions, as a result of e.g. lower transportation costs or a greater consumer basis.