Using precision farming methods to apply lime when correcting soil pH issues is saving farmers money, by cutting the total amounts applied.
Brothers JP and Cobus Bester, farming in the Moorreseburg District of the Western Cape in South Africa, were early converts to precision farming. They have been using a variable rate application plan when spreading lime and gypsum for the past 17 years.
For 15 years this service was supplied by a contractor, but 2 years ago they took over the job themselves with a trailed spreader with variable rate application, working via GPS from a prescription map.
UD Boerdery plants 1,800ha of wheat and medic clover on a 3-year rotation of 2 years clover followed by wheat for 1 year. The clover is grazed by a flock of 1,600 ewes and a 200-strong herd of Nguni cattle, an indigenous breed with ideal characteristics for the this area, which can be very dry.
The clover crop is also harvested for hay for winter feed and for sale as a cash crop in good seasons.
Wheat is harvested by 2 combines, both fitted with systems that provide the information necessary for crop mapping. Prescription maps are created based on protein and carbon levels in the harvested crops, as well as yields and soil sampling.
Top dressing of the following crops is based on these levels. Following the medic clover, requirements can vary from zero up to 60kg/ha, the clover providing much of the necessary nitrogen. Planting is done with a locally manufactured Ausplow planter.
The Besters have found little advantage from variable seed rates with wheat and generally plant at a rate as low as possible commensurate with the current and expected rainfall. This year rainfall has been very low, between 110 and 170mm, compared with an annual average of 400mm.
Cobus, who does the spraying, is very enthusiastic about his new Amazone UX4200 Super trailed sprayer which has a 36m boom with an 11-section control system and individual nozzle lights for night spraying.
This can be a windy area during the day so the ability to spray in the still of the night with GPS controlled steering is a distinct advantage. Ground speed control of the spray rate is also a benefit when operating behind a CVT tractor. The sprayer has the Unitrail steered axle for accurate tracking.