Today’s declaration of drought for the South Auckland, Waikato, Bay of Plenty and Hawkes Bay regions, on top of last week’s announcement in Northland recognises the difficult conditions being faced by farmers across much of the North Island. We appreciate that every property is different, and as such, the only across the board advice we can give is to be pro-active in decision making for your property and business.
Drought relief is being managed by theRural Support Trust, and your local representative can be contacted on 0800 787 254.
Other support agencies include
Federated Farmers Feed Line on 0800 DROUGHT (0800 376 844) and isavailable here.
A Ministry for Primary Industries (MPI) advice note on drought isavailable herewhile MPI drought publications areavailable here.
Coping with stress and depression isavailable here.
Harvesting drought-stressed maize
There is currently huge variation in maize dry matter both within field and between fields. This is influenced by previous rainfall amounts, soil type and compaction, topography, proximity to hedges, trees etc, plant population, and drought tolerance of the hybrid planted.
Given this variability, how can you determine whether your drought stressed crop is ready to harvest at the 30 to 40% Dry Matter stage? Expert advice is available from a number of seed and supply company reps and contractors’ agronomists, so seek their advice and book your contractor well in advance (phoning a couple of days before harvest is not helpful).
Remember that drought stressed crops with few kernels or little kernel development can have high nitrate levels. If green chop is required urgently for hungry animals, get a sample to your vet for nitrate testing before feeding. This is usually a same day service.
Should you wish to assess the crop yourself, here are a few pointers:
• Stand on a high point and ascertain what percentage of the field is still green (particularly from the cob upwards), what percentage is a lighter green but still has folded leaves (particularly during the heat of the day), and what percentage is completely brown and dead.
• If the majority of the paddock is completely brown, harvest as soon as possible.
• If the majority of the paddock is green check the milkline in the kernels, husk cover colour and how many leaves below the cob are totally brown and senesced. As a general guide - if the milkline is starch from the cap to a third, husk cover is turning brown, and the lower leaves are senesced, then contact your contractor. Alternatively, three or four representative plants can be mulched and Dry Matter determined by laboratories or simple microwave testing and weighing.
• Green leaves above the cob will continue to photosynthesise and produce further Dry Matter and yield in the plant. Apart from peat soils (where plants roots can access moisture) most drought-stressed crops north of Taupo are drying down at up to 1% /day.Currently, Dry Matter in Waikato crops that have lost all green leaf colour below the cob is up to3% higher than you would expect if those leaves were still green. This is because the drought stressed stover is becoming very dry even though kernel milkline development is not well advanced
• Many contractors now have NIR Dry Matter determination capability on their choppers, and chop length can be altered to aid stack compaction and the fermentation process of the maize silage.
• The dry weather means that herbicide residues may remain in the soil after harvest and affect subsequent grass seed germination. You can check this by carefully placing the top 100mm of representative soil in a plant tray, sowing some mustard seed, watering and then checking for normal germination and plant health.