Fodder crops are potentially high yielding and play an important role within New Zealand’s pastoral farming system. The potential yield of a fodder crop is affected by the physical and chemical fertility of the soil.

If you are planning on sowing a fodder crop, here are some points to consider.

Paddock selection

Not all paddocks are suitable for crop production, therefore, choosing the most appropriate one is an important step. Correct selection helps determine the yield potential of the crop. For example, paddocks with low yield potential have temperature and/or moisture limitations. This may be because the paddock is in a gully shielded from the sun or located on a north-facing slope. Poor drainage through the spring, low organic matter from being continually cropped, and soil compaction are all issues for consideration too.

One factor in particular stops root elongation and that is soil compaction. Good soil structure is vital to ensuring root development and elongation are not compromised. To identify compacted soil, dig a hole to examine the condition of the soil. If compaction is detected, consider sub-soiling or ripping prior to cultivation to break up the compacted layer. This improves water movement and root penetration through the soil profile.

Soil testing

Once an appropriate paddock is selected, complete a soil test to a depth of 15 cm. Should a test not be taken, growing the crop will be based on guesswork, and this is not a good way of optimising its yield. A small investment in a soil test will pay dividends as it allows your local Technical Field Representative to recommend the correct amount of fertiliser to grow the current crop and ensure soil fertility is maintained at optimum levels for the crops that follow.

Nutrients

Fodder crops usually have a large demand compared to other nutrients for nitrogen and potassium, so these nutrients are usually applied in the greatest quantities. Phosphorus, sulphur and magnesium are needed in much smaller quantities.

Phosphorus is vital in early root development and is recommended to be placed near the seed at sowing. A pH for fodder crops of around 6.0 is usually adequate. Remember, when formulating a fertiliser plan, consider what is going to follow the fodder crop and make sure the fertiliser(s) feed the current fodder crop and leaves soil chemical fertility at an optimum level for the following crop or pasture.

To formulate a fertiliser plan for growing fodder crops this spring, contact your local PGG Wrightson Technical Field Representative.