Environmental implications of three modern agricultural practices: Conservation Agriculture, the System of Rice Intensification and Precision Agriculture

Abstract

Substantial and rapid changes in agricultural land management practices are being made in many countries on all five inhabited continents: Conservation Agriculture, comprising practices that avoid or minimise mechanical soil disturbance, maintain a protective soil mulch cover, and produce crops in rotations or associations; the System of Rice Intensification, in which rice is grown in mainly moist, aerobic soils; and Precision Agriculture, using practices that optimise the use of seed, fertilisers and other production inputs. These management systems provide considerable financial benefits to farmers as well as important environmental benefits, including reversal of land degradation, reduction of river pollution, increased carbon sequestration and reduced greenhouse gas emissions. The nature and scale of these benefits need to be measured and monitored in different agro-ecological and socio-political environments. The reasons for different rates of adoption of these improved practices between and within countries also deserve examination.

Keywords:

• Conservation
• Land husbandry
• No-till
• Rice
• Soil health

Notes

1. Global data on CA are not officially reported. Information on CA adoption is collected from various sources: official statistics (e.g. USA and Canada). Elsewhere, the national estimates given by Kassam et al. [10] based on FAO AquaStat (http://www.fao.org/ag/ca/6c.html) are variously based on survey estimates made by no-till farmer organisations and agroindustry, Ministries of Agriculture, NGOs, and research and development organisations. The information derived from such sources is not up-to-date for many countries, especially for Africa. Accordingly, the data given in figure 1 and table 1 are probably conservative estimates.

2. Since arable literally means ploughable, the term should preferably be avoided in describing CA and ‘annual field crop(s)’ or ‘annual cropland’ used instead.

3. Samples were not taken from ploughed fields. The authors state that most farmers use no-till practices in Santa Catarina State where they worked.

4. A comprehensive description of the SRI database and sources is given in SRI-Rice [25].