Sustainable intensification

The three principles work only together (Global Sustainability):

1. Continuous no or minimum mechanical soil disturbance: seed directly through the residue with a no-till planter.
2. Permanent mulch cover: at least 30 % of the ground covered by residue or a cover crop at all times.
3. Diversification of species: a rotation and mixtures, with a legume, not one crop year after year.

The area so farmed nearly doubled from about 100 to 200 million ha between 2008/09 and 2018/19. The low-tier versions of each — planting through residue, mulch, legume rotations — are in open ground and hold fertility and the farming guide.

Nitrogen use efficiency (NUE) is the nitrogen in the harvested crop divided by the nitrogen applied — fertilizer, manure, legume fixation and deposition. The EU Nitrogen Expert Panel (2015) proposes a target zone for a cropping system:

• NUE between 50 % and 90 %: lower values pollute; higher values mine the soil's nitrogen.
• Nitrogen output above 80 kg N/ha a year in the harvest.
• Nitrogen surplus below 80 kg N/ha a year.

Work out each field's numbers from weighed yields, the crop's nitrogen content and the records of what was applied, every season.

Test the soil of each field at least every few years, and apply only what the crop will take up on top of what the soil supplies: the right source, rate, time and place set out in the farming guide. Split nitrogen into smaller doses timed to the crop's growth, place it near the roots, and credit the nitrogen from manure and from the legume in the rotation.

A computer record or map of each field's tests, applications and yields lets the rate vary from field to field — and within fields where yield maps exist — instead of one rate for the whole farm.

Flooded rice soils produce methane. IRRI's alternate wetting and drying (AWD) drains the field periodically to a threshold, usually 15 cm below the soil surface, then re-floods it. It reduces the water used by 30 % and methane emissions by 30–70 %, without a yield penalty.

• Install a perforated tube in the paddy, open at the bottom, and watch the water level fall inside it below the surface.
• Re-flood when the water in the tube reaches 15 cm below the surface.

Prevent, watch, then treat: resistant varieties, rotations and natural enemies first; scout the fields and count the pests; spray only when a count passes the economic threshold, with the least hazardous product and the right protective equipment. The ladder and the pesticide rules are in the farming guide; highly hazardous pesticides stay banned, as in the Green Revolution's bill.

An estimated 13 % of food is lost after harvest and before retail (FAO, 2019), and 19 % of food available to consumers — 1.05 billion tonnes — is wasted at retail, in food service and in households (UNEP, 2024); 60 % of that waste is in households (FAO).

• Harvest on time and dry grain to safe storage moisture before it goes into store (preserve the harvest).
• Store in clean, sealed, pest-proof containers or stores, and check them.
• Move perishables cold and fast: the cold chain for fruit, vegetables, milk and fish.
• Measure losses at each stage — field, threshing, store, transport — so the largest is fixed first.

Judge a practice by what it does on the farm, not by its label. For every field, every season, record yield, nitrogen in and out, water used, pesticide used and post-harvest loss.

FAO's 10 elements of agroecology, approved by its 197 Members in December 2019, give a checklist for the whole system (FAO): diversity, synergies, recycling, efficiency, resilience, co-creation and sharing of knowledge, human and social values, culture and food traditions, responsible governance, and circular and solidarity economy. Use it to find what the farm lacks, and the field records to show whether a change worked.