Precision farming the way to go
The day a seed is planted is the most important in its life and can have the greatest effect on its potential to deliver.
“Get the crop canopy too thin, with not enough seed, and the crop isn’t intercepting enough sunlight or can’t compete with weeds.
“Too thick, and the plants are competing for precious resources like fertiliser, moisture, sunlight and have a higher lodging risk,” he says.
“Our initial attempts at variable rate seeding involved a manual system, pressing a button in the cab to raise or lower the seed rate depending on soil type.
“It had its limitations. For instance, you were relying on the operator to decide where the field variability starts and stops. For automated variable seed-rate technology to work, an additional investment is required, in soil conductivity testing and soil type interpretation.
“This involves passing a magnetic beam over the soil and monitoring the returning signal. From this data, soil types across the field can be mapped. This is a one-off cost in the region of £15 per hectare. When we know the soil types, we can draw up a map of the expected seed germination rate. Variable rate seeding is the first step in integrated crop management, ensuring that all plants are at the same growth stage for precise fungicide timings, and to reduced lodging in more fertile areas.
“The equipment used can also record the seed rate applied for monitoring and final yield comparison.
At Overbury, the initial cost of variable rate seeding is £15 per hectare, which can be written down over five years. Seed rate maps are 50 pence per hectare. The annual cost therefore is £3.50 per hectare.
“Assuming the total seed use stays the same, at £150 per tonne, we only need an increase of 23kg per hectare per year to break even,” said Mr Freestone.
“There should also be scope with this system to reduce soil runoff down tramlines by placing bands of seed in the tramlines at specific intervals. These seeding bands would act to intercept water and soil, carrying fertiliser and pesticides as it flows down the tramlines through the winter.”
He asked: “Do you just want a tractor that steers itself so you can spend time checking your twitter account, or do you want to be fully integrated with seed, fertiliser, sprays and yield mapping?
“The latter will allow you to build modules that communicate with each other and avoid wasting money on systems that are not compatible. Can the hardware in the cab be moved around from vehicle to vehicle? There is no point in a system sitting in the combine when you could be drilling with it.
“Thirdly, can the information you gather be used to make better decisions?
“An example is harvest yield data can be converted into nutrient off-take maps for fertiliser applications the following year. Do not however, underestimate the amount of time you need to set up the systems or organise the data into a useable format. Finally, identify the training needs of the people who are going to use this machinery. Driving a tractor can be very different from using a USB stick to change the rate of fertiliser on the move. But precision farming has a long way further to go. Looking further into the future could we see robots in arable or vegetable fields, planting seeds, recording where they were planted, returning two weeks later to check on germination and if necessary replant?
“Robots are already capable of identifying weeds with cameras and micro-dot spraying a choice of selective herbicides, reducing total herbicide use by 99.9%. Others are using lasers to remove the need for herbicides at all.
“We could see smart drains that have nano-barriers to keep fertiliser and pesticides in the soil where the plants need them. They would have the ability to shut themselves off in the summer to retain moisture in the soil and open again to release clean water during the winter months. ”
