Soil moisture levels are important for successful, bountiful harvests each year and healthy fields. Even if you’re not deeply invested in the science of precision agriculture, there are still times when you need to carefully monitor and manipulate your growing conditions to produce crops at their optimum.
Most of the time, soil moisture level is out of our control. Sure, we can use weather and climate data to plan our sowing around optimum times, but we can’t control how much it rains and when.
Irrigation should be the simple solution to increasing soil moisture levels, but even that’s not straight forward. How do you control where the water is sitting within the soil? How can we tell when roots are getting the optimum amount of water and when the fields need a top up? New technology could be the answer.
Below we’ve outlined 5 different ways to either increase or decrease soil moisture levels to get your fields in the best shape this season.
Whether you’re using the tractor to spray on that extra moisture acre by acre, dropping water from aerial drones or manned aircraft or setting up a network of sprinklers, you’re going to face problems with this method of increasing soil moisture. It’s just not that efficient.
While the aerial method of spraying your fields sounds time efficient, it really isn’t the best option. Of the 3 spraying methods mentioned above, it’s the most susceptible to drift and evaporation. It’s just not that accurate unless you have the funds available to invest in some high-tech drone equipment that can calculate how to drop the water most efficiently.
Using a tractor to drive through your fields spraying water does give you a greater element of control, but it is also very time consuming. We’d recommend this if you just need to add moisture for the short term until the wet weather picks back up.
Drip irrigation is much like a network of sprinklers but much better. This technology isn’t the cheapest and it does have some disadvantages, however it really seems to be the best solution to nourish dry fields that need some extra soil moisture to see your crops through.
A rigid structure of pipes set up throughout your fields can drip water and nutrient solutions right to the base of each plant, reducing the chances of evaporation and delivering water only where it’s needed. This is a great system but takes quite some planning to set up and remove when you need to harvest crops. Once it’s all set up you can adjust the pressure to drip more or less water across your field depending on the soil moisture levels. One of the main problems with this irrigation network is the tiny holes that let water drip out of the pipes – they can get clogged up and aren’t suitable for herbicides that need to be sprinkled to be activated.
One ingenious solution that we’ve seen in recent years is the Figaro irrigation platform of sub-soil material tubes that slowly ‘weep’ water to plants only when the soil moisture level reduces. This means there’s no chance of evaporation at all as the water is delivered straight to the roots. Still, you’ll need to go through the hassle of removing it before/after harvest, and it’s not so straightforward to fix if there’s a problem somewhere within the underground network.
By tilling your soil, you’re reducing moisture in a number of ways. Firstly, any moisture that’s lingering below the top soil layer will be brought to the top to dry out or evaporate. Secondly, if your fields are hard and without any cracks for water to drain, tilling can introduce water that would otherwise build up and flood down into the soil to be drained away.
You’ll want to be careful with this method. While breaking up the soil will allow moisture to penetrate, you risk too much soil degradation if you’re tilling after every rainfall, which could be just too much for your fields to handle.
There are further disadvantages to this method, including exposing top soil which could result in soil erosion and compacting the soil further, preventing moisture from draining.
This method is best if you’re looking for a 1 time, quick solution before you’re ready to sow. It is not suitable in the long term.
Burning any remaining crops or crop residue is another method of reducing soil moisture levels, although it’s not the most popular. Many farmers believe that by burning off the old, dry or unwanted vegetation you make room for fresh new shoots and healthy plants to grow.
Burning residue crops, weeds and other vegetation on fields will reduce moisture by evaporating it from the soil. Burning will also kill off any pests and even help to combat diseases… however fire isn’t selective. It will also burn off the micro bacteria and organisms living in the soil that your fields need to maintain soil nutrition levels and keep the fields aerobic and porous.
You’ll need to be careful that your fire doesn’t spread to other fields, hedgerows, woodland or residential areas. Keep the fire on the field and take steps to control it.
Deep below your fields there will be water networks, wells and maybe even rivers and lakes. Each time it rains and your soil gets too moist, that rainwater will begin to drain down into these subterranean networks. By draining these networks, or creating your own network, you’re making more room for soil moisture in the top soil of your fields to filter down.
The problem with this method of reducing soil moisture is that it’s hard to control and you’ll need somewhere to drain the water to. Building a drainage system and ditches is going to cost money and take up a fair amount of time. Furthermore, depending on the location of your farm, you may not be able to dig deep at all if there are underground pipe and tunnel networks.
The best solution to soil moisture level problems is to treat your fields with respect and take precautionary steps rather than trying to deal with the moisture problem later. If you’re continuously having problems with soil moisture levels you might want to look at cover crops, altering and diversifying your crop rotation and surveying your field soil types to better understand what crops your farmland is suited to.