Agriculture is an ancient activity, whose main objective is to supply food to the population and, therefore, it is the most important human activity. Since prehistoric times, humanity has used the fruits of agricultural production for subsistence and, later, for the production of surpluses. However, the way farmers use the land has changed a lot, especially in recent decades, with the increase in the world population. The results of this change have not only been positive, since, with regard to natural resources and the environment, there is a great concern: how to exploit natural resources consciously, so that future generations can use these same resources?
As already mentioned in the text “What is sustainability in agriculture?” (available here: https://ilsabrasil.com.br/o-que-e-sustentabilidade-na-agricultura/) the idea of agricultural sustainability revolves around three main elements: reduction of environmental impacts, social impact and economy. Based on this, for an agricultural system to be sustainable, it must encourage environmental conservation in a way that does not put the other two elements at risk. Any and all agricultural activities to be considered sustainable must allow for the rational and conscious use of water and soil, promote the reduction of greenhouse gas (GHG) emissions and maintain life in the soil.
According to Possantti (2019), water is a resource that can be considered both renewable and non-renewable, everything depends on consumption and the means and place of extraction. However, according to this author, in a finite world, all natural resources are limited. Non-renewable natural resources are limited by the size of the stock and renewable resources by the capacity and speed of regeneration.
With the advancement of climate change caused by human actions, rainfall patterns have also been undergoing transformations. The occurrence of acid rain more frequently is one of them. This type of rain occurs due to the mixture between water vapor and polluting gases – especially sulfur and nitrogen oxides (SO3 and NO2), released mainly by intense industrialization. When they precipitate and fall to the soil, they cause acidification of the environment, in addition to being toxic and non-metabolizable by plants.
In addition to acid rain, the intensification of agricultural crops with indiscriminate use of pesticides can, according to Lopes and Albuquerque (2018), contaminate water reservoirs, rivers, water resources and river basins, and may interfere with aquatic living organisms. Therefore, if these compounds are not used consciously, future generations may be affected by the reduction in the availability of drinking water and/or water suitable for agriculture. Also according to the authors cited above, some substances that have been banned for decades in Brazil, such as hexachlorocyclohexane (HCH), are still being detected in water samples, wells and springs.
Another important factor to be considered here is the impact that some of these substances can have on pollinating insects, such as bees, increasing the mortality of these organisms that are so important for agriculture, if these compounds are not used consciously. With regard to soil organisms, many pesticides, if used correctly, are considered harmless, but the use of doses above the permitted level – and depending on the physical, chemical and biological characteristics of the soil in which they were deposited – can directly or indirectly influence the population of macro and microfauna, as is the case with the herbicide glyphosate (Moraes & Rossi, 2010; Zilli et al., 2008; cited by Belchior et al., 2014). This can irreversibly compromise soil fertility, since these organisms are responsible for nutrient cycling and biological nitrogen fixation.
Soil is considered the foundation of life on the planet and is also a non-renewable natural resource. Improper soil management, such as the removal of green cover or straw (post-harvest), can contribute to the erosion of surface layers, causing loss of fertility. The intense use of mineral fertilizers – such as urea – can also cause soil salinization. According to Melo and Voltolini (2019), this process can affect all soil fauna and flora, reducing biodiversity in terrestrial and aquatic ecosystems and the efficiency of nutrient cycling, also contributing to erosion processes caused by rain and wind.
Furthermore, intensive exploitation without due care can lead to an even more extreme case of soil degradation: desertification. This process occurs when there is complete chemical and physical degradation of the soil, which loses its productive characteristics and becomes infertile and unsuitable for agriculture. According to the Ministry of Science, Technology and Innovation, the most degraded areas generally have low phosphorus levels in most of their soils. Nitrogen is also very scarce, due to the low levels of organic matter. With the suppression of vegetation and the low capacity for green mass production, when it rains, the remaining organic matter in the bare soils is quickly mineralized, further aggravating the deficiency of nitrogen, water and food. The desertification process, in many cases, is considered irreversible – or at least difficult to solve.
In all areas, the absence of conservation practices that promote sustainable farming and the conscious use of natural resources can result in irreversible changes in agricultural systems, making the production of food and other products from agriculture increasingly scarce or more expensive. Therefore, any decision-making must be made with a view to exploiting these resources in a way that causes the least possible environmental impact, while ensuring the economic and social aspects. Alternatives to this exist and are increasingly accessible.
One example is ILSA's replacement of mineral fertilizers with organomineral fertilizers, since the entire production process is sustainable, in addition to using byproducts from other industrial processes that would otherwise be discarded into the environment to manufacture its products. Furthermore, these fertilizers stimulate the full development of soil microorganisms, since they have a low C/N ratio. They also provide gradual and uniform release of nutrients, which will be made available throughout the harvest, thus avoiding product waste due to leaching and also the number of applications, reducing the environmental impact.
Bibliographic references
BELCHIOR, DCV; SARAIVA, AS; LÓPEZ, AMC; SCHEIDT, GN Impacts of pesticides on the environment and human health. Science & Technology Journal, Brasília, v. 34, n. 1, p. 135-151, 2014.
LOPES, CVA; ALBUQUERQUE, GSC Pesticides and their impacts on human and environmental health: a systematic review. Saúde em Debate [online], v. 42, n. 117, 2018.
MELO, RF; VOLTOLINI, TV Rain-dependent family farming in the semi-arid region. Embrapa Semiárido, Petrolina, 2019. 467 p.
Ministry of Science, Technology and Innovation – available at: https://www.gov.br/mcti/pt-br/rede-mcti/insa/assuntos/noticias/entendendo-sobre-desertificacao-conceitos-caracteristicas-causas-consequencias-e-solucoes
MORAES, PVD; ROSSI, P. Environmental behavior of glyphosate. Scientia Agraria Paranaensis, v. 9, no. 3, p. 22-35, 2010.
POSSANTTI, IB Systems thinking and water resources: when will the water run out? UFRGS, hyperlink: https://www.ufrgs.br/warp/2019/10/06/pensamento-sistemico-e-recursos-quando-agua-acabar-hidricos/. 2019.
ZILLI, J. É.; BOTELHO, GR; NEVES, MP; RUMJANEK, NG Effect of glyphosate and imazaquin on the bacterial community of soybean rhizoplane (Glycine max (L.) Merrill) and on soil microbiological characteristics. Brazilian Journal of Soil Science, v. 32, n. 2, p. 633-642, 2008.
Authors
- Agricultural Eng. Msc. Aline Tramontini dos Santos
- Agricultural Eng. Msc. Carolina Custodio Pinto
- Agricultural Eng. Msc. Thiago Stella de Freitas
