Nutrient Management for Small Farms

What is nutrient management in plain terms?

It is a simple cycle. Find out what the soil holds, decide what the crop needs, apply sources that fill the gap and keep records so you can adjust. Too little limits growth, and too much wastes money and can wash into water.

The approach works the same whether you grow a market garden or hay for a few animals.

Nutrients move. Nitrogen in particular can leave a field as nitrate in drainage water or as gas, and phosphorus tends to travel with soil particles in runoff. Understanding how each behaves explains why timing and placement matter, and why erosion control is part of nutrient management.

What is the first step?

Test the soil. A soil test reports pH and nutrient levels and, with the right lab, gives recommendations tailored to your crop. Take samples by the lab's instructions and sample different fields or beds separately.

Retest regularly, since levels change with cropping, weather and applications. Keep each report for comparison.

Sampling well makes the test worth it. Take multiple cores from each management area, avoid odd spots such as old manure piles, and follow your lab's depth instructions. Mixed samples from areas with different histories can hide real differences, so keep them separate.

How do I count the nutrients I already have?

Manure, compost, cover crops and legumes all contribute nutrients. These are often overlooked, so a farm that adds manure every year may already have plenty. Ask your extension office how to credit these sources in your area.

Compost and manure vary widely in content. A lab analysis of your own material is more reliable than a general guess.

Livestock operations have an additional source. Animals eat nutrients that are then returned in manure, so a farm that feeds purchased feed may be importing nutrients without noticing. Tracking feed, manure and crop removal helps you see whether nutrients are building up or running short.

• Keep a log of every manure, compost and fertilizer addition.
• Credit previous legume crops where guidance exists.
• Test manure or compost if you apply large amounts.

How do I choose the source, timing and placement?

Different sources release nutrients at different speeds. Quick sources suit crops with fast demand, while slow ones build supply over time. Apply close to when the crop will use them and avoid frozen, saturated or steep ground where runoff is likely.

Place nutrients near roots where practical instead of broadcasting widely. Always follow the label, since the label is the law, and use your soil test to set amounts rather than a rule of thumb.

Take weather into account. Wet soils and heavy rain increase loss, while dry spells reduce plant uptake. Split applications and waiting for a clear forecast reduce risk. Avoid spreading ahead of heavy rain, and keep an eye on forecasts from the National Weather Service.

How do I protect water?

Keep a buffer of permanent vegetation along streams, ponds and ditches. Keep applications away from wells and sinkholes. Cover crops hold nutrients in place between crops.

Some states set rules on manure and fertilizer application near water, so ask your state agriculture or environmental agency what applies to you.

What records and plans should I keep?

A short notebook or spreadsheet is enough: field name, crop, soil test date, what you applied, when and how much. Over a few seasons it shows which fields need more, which need less and whether your changes worked.

Your NRCS office or extension agent can help write a simple plan, and some programs support planning. Ask what is available locally.

Review your plan each year. Crops change, fields change and soil tests change, so a plan written once becomes stale. Set a date after harvest to compare what you applied with what the crop needed and what the next test shows.

How does nutrient management fit with pasture and hay?

Pastures and hay fields remove nutrients with every cutting, and animals redistribute them unevenly, concentrating them near gates, shade and water. A soil test of the pasture shows whether phosphorus, potassium and pH need attention, and nitrogen is often supplied by legumes in the sward.

Rotating animals, spreading manure evenly and keeping a record of hay removed help keep nutrients in balance. Ask your extension office for pasture soil test guidance, since recommendations differ from those for vegetable gardens.

Last reviewed: November 12, 2026. Written by the Homestead & Small Farm Editorial Team. See our editorial policy.