Nutrients as capital . An agricultural ecosystem differs from a natural one in that plant nutrients are constantly being removed and exported. In practice, the quantity of nutrients available for recycling via plant and animal residues is rarely sufficient to compensate for the amounts removed in agricultural products, even in low-productivity farming. In addition, losses inevitably occur, even in the best-managed systems. Consequently, mineral fertilizers have to play a key role in areas where increased agricultural production is required.
Farmers apply plant nutrients only if their effects on crop yields are profitable.
The pursuit of higher production has to be balanced against the need to maintain soil fertility and avoid soil degradation. The profitability of adopting IPNS should, however, be viewed over the long term, since improved efficiency in crop nutrient use tends to become apparent only after several seasons. The removal of access constraints to markets and production technology, and protection from risks, would allow farmers to use plant nutrients economically and in ways that support sustainable crop production. Advice on efficient plant nutrition . Providing good advice to farmers and enhancing their decision-making capacity is the best way to promote the sustainable intensification of agriculture.