This promotional feature was provided by Ballance Agri-Nutrients
Summer forage crops are a useful feed source when pasture quality is poor and thanks to their high-quality feed profile, they deliver good results when used for finishing stock or for milk production.
When growing crops for late summer feed, soil testing and selecting the right fertiliser is essential for achieving optimal results.
Summer forage crops are generally planted as part of a pasture renewal cycle, so often the poorest performing paddocks are chosen. If the nutrient status and physical condition of these paddocks are not addressed before planting, yields are likely to be restricted.
Soil testing (ideally 6 months before planting) provides you with the information to adjust soil pH (as a rule of thumb, it takes 1 tonne lime/ha to raise the soil pH by 0.1 unit) and correct any shortfall in the nutrient status prior to planting.
Pay particular attention to the available nitrogen (N) test results. This test measures how much nitrogen the soil can potentially supply for plant use over the growing season. This helps you identify the amount of fertiliser N you need to apply to reach your expected yield.
Applying N helps the crop reach its agronomic potential, however, applying too much N will reduce the
economic yield of the crop. Targeting nitrogen applications to expected yield minimises waste and maximises the return on your nitrogen investment.
If cropping former ryegrass and clover paddocks, considerable quantities of organic N may be mineralised from the soil, following tillage practices. Alternatively, if the land has been cropped and cultivated over a number of seasons, organic N reserves may be low.
The choice of fertiliser and rate of application depend on the soil nutrient status and the method of sowing.
Sowing crops with a starter fertiliser, such as di-ammonium phosphate (DAP), provides plants with readily available phosphorus (P) to support developing roots and N to support early growth.
Be mindful of micronutrient levels, especially with brassicas, which may need boron at planting to prevent brown heart symptoms and enhance yield. Cropzeal Boron Boost, contains boron in every granule, delivering the micronutrient more evenly to the crop than is possible by including granular boron in a fertiliser mix.
Nitrogen side-dressing timing depends on the crop and the season. It's important for nitrogen to be available to the plant at a time when it can enhance canopy growth, thereby increasing the plant’s ability to convert sunlight into energy, resulting in improved yield.
Generally, the first post-emergence dressing can be applied 4 to 6 weeks after sowing. With multiple graze crops, further light dressings of N, such as 60 kilograms of SustaiN per hectare, can be applied after grazing.
Consider monitoring crop nitrate levels to reduce the risk of animal health issues, as applying N too late in the season when growth is slowing, can elevate levels.
Where high rates of nitrogen are broadcast, the potential for loss is increased when conditions favour volatilisation i.e. whenever rain is not certain following application. In these circumstances SustaiN can help reduce the loss of N by volatilisation, retaining more of the applied N in the soil to be utilised by the plant.