Conservation Agriculture and Climate Change

Abstract

This chapther review aims at developing a clear understanding of the impacts and benefits of Conservation Agriculture with respect to Climate Change, and examining if there are any misleading findings at present in the scientific literature. \ud Most of the world’s agricultural soils have been depleted of organic matter and soil health over the years under tillage-based agriculture (TA), compared with their state under natural vegetation. This degradation process can be reversed and the review identifies conditions that can lead to increase in soil organic matter content and improvement in soil health under Conservation Agriculture (CA) practices which involve minimum soil disturbance, maintenance of soil cover, and crop diversity.\ud The review also discusses the need to refer to specific carbon pools when addressing carbon sequestration, as each carbon category has a different turnover rate.\ud With respect to greenhouse gas emissions (GHGs), sustainable agricultural systems based on CA principles are described which result in lower emissions from farm operations as well as from machinery manufacturing processes, and that also help to reduce fertilizer use. \ud This review concludes that terrestrial sequestration of carbon can efficiently be achieved by changing the management of agricultural lands from high soil disturbance TA practices to low disturbance CA practices and by adopting effective nitrogen management practices to provide a positive nitrogen balance for carbon sequestration. However, full advantages of CA in terms of carbon sequestration can usually be observed only in the medium- to longer-term when CA practices and associated carbon sequestration processes in the soil are well established

A new analytical framework of farming system and agriculture model diversities. A review

“…Regarding biological regulations, two main complementary strategies can be distinguished: (i) developing direct effects of plant biodiversity on pathogens, animal pests and weeds via, for example, traps, barriers and resource dilution effects and the breaking of pest cycles ("bottom-up" effects) and (ii) developing effects of planned biodiversity and non-crop habitats on naturally occurring associated biodiversity, which provides biological control of weeds and animal pests ("top-down" effects of natural enemies) (Altieri 1999;Fahrig et al 2011;Letourneau et al 2011;Ratnadass et al 2012;Tscharntke et al 2005Tscharntke et al , 2012. When biodiversity-based farming systems use chemical or biological inputs to increase production beyond the level allowed by input ecosystem services alone, they must use them sparingly to avoid reducing expected short-and longterm benefits of the input ecosystem services (Duru et al 2015a;Pisante et al 2015). As shown by Biggs R et al (2012), to increase the level and resilience of ecosystem services, these farming systems must manage three key properties of agricultural ecosystems: diversity-redundancy, connectivity and slow variables.…”

How to implement biodiversity-based agriculture to enhance ecosystem services: a review

“…5. In diversified systems, farmers seek to avoid soil disturbance to favor beneficial associated biodiversity and use exogenous inputs sparingly to not reduce expected short-and long-term benefits of input ecosystem services (Pisante et al 2015). During this transition (Fig.…”

“…Implementation of only one or two of these principles may lead to negative effects, especially on yields (Pittelkow et al 2014). Furthermore, a single tillage event may significantly damage soil quality, since it can lead to loss of sequestered soil carbon and years of soil restoration (Pisante et al 2015). During this transition, farm managers must implement new agricultural practices, often ill-known, to develop agroecosystems with a high level of diversity-redundancy and connectivity that correspond to "complex adaptive systems" (Biggs et al 2012).…”

Diversification, Yield and a New Agricultural Revolution: Problems and Prospects

“…Conservation agricultural also reduces the negative externalities of green house gas emissions, nutrient loss, erosion and run off while improving water quality and retention (reviewed in [109]), soil and above ground biodiversity [41,109]. The push-pull system of conservation agriculture also enhanced positive externalities through bolstering small livestock production, functional biodiversity, incomes and women's empowerment [57,59].…”