It makes sense that previous year’s crops and any residue leftover will impact this year’s yield, yet few of us go further than checking our herbicides won’t kill our crops before going right ahead and sowing.
We might test the soil a little, check the acidity and plan crops in accordance, but beyond tilling our fields and spraying the appropriate herbicides, we don’t take any precautions. We’ve already covered in multiple articles how precision agriculture is the way forward for many, so it should come as no surprise that precision agriculture methods will be the way to solve these residue issues.
Make no mistake, we’re not suggesting that all residue is bad, simply that left unchecked you’ll either be damaging your crops or throwing away a golden opportunity to boost your yield without investing in fertilisers.
Pauley Bradley, product manager for the mass agriculture resource supplier John Deere, has found 4 ways that residue is affecting crop yields on farms across the world. Here they are and here’s what you can do to manipulate these crop residue build-ups on your own farm.
Try these out, record the level of yield improvement and let us know your results.
1 – Prevent Seedling Emergence
A heavy layer of residue weighing down your fields can really have a negative effect on crop germination rates. So that residue locked in all the nutrition in the field, protecting it from erosion and saving it for your crops…. Now even if your seeds get in contact with that nutritious soil (see the next point) there’s still a fair chance that residue will shift back over and prevent germinating seeds from reaching the top.
First, consider how strong your crops are, perhaps try a variety with especially strong roots and stem, secondly you can reduce and spread your residue either by tilling or planting a cover crop that leaves minimal residue.
2 – Contact between Seed and Soil
It goes without saying that residue left on the top soil is going to really prevent seed and soil contact. Of course, we can just go and till our fields to mix things up a bit, but if you’ve left uneven amounts of residue from last harvest, you might not be doing much good.
This is why you need to start planning and thinking about next year’s crops before you even harvest this years! Take a few minutes to work out a simple plan of depositing residue evenly and you’ll already have taken a big step towards yield improvement a year ahead of time.
3 – Impact on Soil Temperature
An extra thick layer of decomposing crop or residue is only going to decrease the temperature of the soil. Your first thought might be that residue will increase the temperature of the soil, it’s actually the opposite that happens. The deeper the residue, the further the sun’s rays have to penetrate to warm the soil to optimum.
In early spring, this could delay your sow date by several weeks. However, if you’re farming in a hot climate, that layer of residue can keep your soil cool enough to grow crops not suited to your environment. Try to plan for your strengths.
4 – Nitrogen Deficiency
To digest the residue naturally, microbes need a healthy supply of nitrogen. By planting your crops when there’s too much residue in the soil, your crops will be competing with these microbes for a supply of nitrogen. This is especially prominent in early spring, when temperatures start to rise as mentioned in the previous point.
In fields with heavy residue, consider upping the amount of nitrogen you apply. Or if you’d prefer to go down a chemical free, organic farming route, try a crop that doesn’t need quite so much nitrogen as others, although keep in mind that all crops will need nitrogen at some level.
So that’s it. 4 ways you probably didn’t know residue was affecting this year’s crops. There’s bound to be more ways, some good and some bad, so keep a good record of your residue on the farm. If you’ve been following our articles on farm management, you’ll already be super organised so quickly stepping out to record some residue figures each harvest is just another little way you’ll be improving your farm.
And of course, give your thanks to Pauley Bradely for starting what could be an interesting study into the effects of different crop residues on farms around the world.
We sincerely hope that you take this newfound knowledge to make huge changes on your farm. After all, it’s the farmer with the biggest drone or shiniest tractor that’s the most successful – it’s the farmer that pays attention to the land, and makes calculated, informed decisions to improve yield and play to his own strengths.
Make a note in your calendar for a week before sowing time; it may be too late to start planning ahead but with a few of the tips below you can still make something of a yield improvement this season.