Ecology (the processes that influence the distribution, abundance and interactions of organisms) and ecosystems (the interaction of a community of organisms with their environment) have underpinned agriculture since the beginnings of domestication and cultivation. Our food comes principally from managed agroecosystems (modified natural ecosystems created by farmers), as well as from marine and freshwater systems or forests. Within each agroecosystem, the diversity of the original field biodiversity (the variety of different types of life found on earth) is reduced to a limited set of crop, pest and weed species. However, many of the basic ecological processes remain the same. Ecological Intensification seeks to create sustainable forms of crop and livestock production.
Ecological Intensification involves using ecological processes more intensively in a sustainable manner. The aim is to use land, water, biodiversity and nutrients more ecologically efficiently and in ways that minimise negative environmental impacts. The ecological principles and practices that can be used to sustainably intensify the agroecological system include the processes of competition and mutualism between crops and weeds, herbivory of crops by pests, predation of pests by their natural enemies and the decay of organic matter. Ecological Intensification is one of the three pillars of Sustainable Intensification, alongside ‘Socio-economic’ and ‘Genetic Intensification’. When aiming to sustainably intensify an agroecosystem, it is beneficial to include elements of all three pillars.
Ecological Intensification includes building natural capital, precision agriculture and diversification. Natural capital (the biophysical assets within the natural environment that deliver economic value through ecosystem services) can be conserved and enhanced through a variety of approaches, including organic agriculture, water conservation and conservation agriculture.
Precision agriculture aims to ensure that inputs – whether of nutrients, pesticides, seeds or water – are used in a precise and strategic way so ensuring that they are used sparingly and effectively with minimal environmental impact. Knowledge of sustainable farming practices that protect natural capital for smallholder farmers is limited, as is access to the right types of inputs in remote parts of sub-Saharan Africa. The prudent and targeted use of inputs such as fertilisers helps to improve soil quality and moisture whilst minimising the environmental impact that excessive use can cause. Precision farming can be achieved with methods such as microdosing, soil testing and seed spacing.
Diversity is the number and relative abundance (how common or rare a species is relative to other species in a defined location) of different species – both flora and fauna – that are found at a given site, or field. Diversity is generally considered a key factor in maintaining stable and resilient agroecosystems. Conventional agricultural systems comparatively are simplified natural ecosystems to maximise the production of a limited number of crops or livestock. This has led to a significant loss of genetic diversity of domesticated plants and animals.
Diverse agroecosystems can have multiple benefits when varieties or species are grown together with minimal competition or if there is a mutual beneficial relationships between them. Mixtures of crops can provide for a diverse and healthier diet, deter pests, and during times of crises such as drought or cyclone, can provide a form of insurance when at least one crop out of many survives. Diversification can be achieved with the use of multiple cropping, agroforestry and integrated pest management (IPM).