🇬🇧 Maintaining your soil and stock during periods of wet weather

What continuous wet weather can do to soil structure

Soil is at its most vulnerable when wet. Typically, healthy soils contain air pockets. This allows oxygen to circulate, promoting microorganisms as well as creating good soil structure. If soil becomes waterlogged, then these pockets of air are pushed out reducing biological activity. Waterlogged soils are more prone to compaction, so cultivation should be kept to a minimum or you can pause work until conditions improve.

A loss of soil structure can cause it to slump. When this soil eventually dries it can form a hard-set layer which is difficult to cultivate.

How wet weather affects sheep

When lambs’ wool is wet, they use a lot more energy trying to keep warm. They spend more time sheltering from the adverse weather rather than grazing. Therefore, finishing times and weights can be delayed. Poor weather conditions also make sheep more susceptible to some conditions. Dermatophilosis is spread more easily, and foot rot is more prevalent and contagious during wetter weather.

If wet weather is followed by a period of warm sunny weather, then grass can grow rapidly. This often means minerals in the grass are diluted such as cobalt and magnesium which affects lamb growth rates and increases their risk of getting staggers.

How wet weather affects cattle

Mineral levels in pasture affected by wet weather also have consequences for cattle. Grasses reduce their uptake of minerals in waterlogged soils. Heavy metals are sometimes more easily absorbed by the plant subsequently affecting the availability of magnesium, calcium and phosphorus.

Some parasites thrive in wet weather. Lung worm matures in cow pats lying dormant until the rain washes the faecal matter away. Infected pasture is then ingested by the cattle. In warm, wet conditions, this lifecycle (releasing hundreds of larvae), can take as little as five days (6).

Other implications of wet weather and how to prepare

Excessive rainfall effects the amount of slurry produced by dairy farms. Contaminated standing water is detrimental to the environment and unlidded slurry tanks fill up more quickly. Spreading slurry on waterlogged soils is also problematic; it runs off the land and can contaminate waterways.

Furthermore, if soil is too waterlogged then drilling isn’t possible as machinery can get stuck, and seeds can become damaged. Harvests are affected resulting in losses for arable farmers. Limited straw production affects livestock farmers who must look elsewhere for bedding. With more livestock housed indoors due to the poor conditions even more straw is in demand and shortages can occur quickly.

Indoor-housed animals have to rely on conserved feed. Buying in silage and hay, and straw or sawdust for bedding, for prolonged periods adds to farming costs.

Outwintering livestock could help to alleviate some of these problems. Not all soils will tolerate this but for those that can, animals should be regularly moved from field to field throughout the wetter winter months. If done effectively, this can reduce housing costs, rejuvenate the soil, and improve animal production. For more information about outwintering, see our blog post on outwintering.

Straw pads for wet weather.

If this method isn’t appealing, then creating a ‘straw pad’ is another alternative to housing livestock during winter months. This is an outdoor paddock that you bed with straw that you replenish regularly. It has all the benefits of outwintering cattle such as improved animal health and welfare, reduced pasture damage and land poaching, but it doesn’t require solid housing and the associated costs.

A lot of harvested straw is wasted when it becomes wet. Storing large straw bales can be challenging but leaving them in the field can be costly. There are now hay bale stack covers on the market which can cover large stacks and keep them dry during periods of heavy rain, minimising losses.

What are some short-term things you can do to mitigate?

Moving cattle around regularly during wet weather can reduce damage to both pasture and soils. Well-drained fields or sacrifice fields help to minimise the impact. Grazing management is important to ensure a resilient pasture. Overgrazed grasses recover slowly and sustain more grazing damage during wet conditions.

Calving and weaning can take place indoors to avoid damage to fields. There are advantages to this in that farmers can keep an eye on the animals and have more control over the weaning process. You can release calves onto pasture with cows joining them later when conditions improve. Housing heavier cattle for longer whilst lighter animals are allowed out to graze reduces ground damage. The concern with indoor rearing is the risk warm wet conditions pose to calves developing pneumonia.

Driving heavy machinery along farm edges can destroy field margins. Swapping a tractor for a small Kubota to check livestock, for example, can reduce the impact heavy tyres have on the soil.

What are longer-term options?

When establishing new pasture, often sewing grass using a no-till method withstands wetter weather better than grass established on tilled land. Maintaining a heavy sod can increase pasture resilience. This can be achieved by overseeding, avoiding over grazing, and regularly testing soil health and making adjustments to maintain it. Withdrawing moisture from the soil by planting a cover crop can help to alleviate some pressure from excessive rain. However, crop residue such as stubble, can help maintain soil structure and drainage of soils.

What can we learn from other countries?

Farmers in Bangladesh, renowned for its heavy monsoons, have adapted their agriculture to a very wet climate. During the dry season, they pump vast volumes of groundwater onto their rice paddies. This has tripled their rice production and, whilst their groundwater almost runs dry each year, as soon as the monsoons arrive the aquifers are completely refilled. This method of farming significantly reduces the amount of flooding when the rains come.

Other Bangladeshis have turned to ‘floating farming’ whereby fruit and veg are grown on floating mats of vegetation. This means that they can farm year-round regardless of the weather.

We are not suggesting that we begin growing our cereal crops on floating mats or deplete our groundwater during dry periods to limit the effects of subsequent floods, but farmers in the UK will have to adapt to the changing climate one way or another.

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