Tag: sustainable farming

The importance of managing manure on-farm 

Posted on January 11, 2024 by - Insights, News

Written by Becky Willson, Business Development & Technical Director.

Manure is a fantastic on-farm resource. This is because it can deliver a source of nutrients that can be used to grow crops, as well as enhancing soil biological activity, feeding the soil microbes and helping provide a steady supply of organic matter. This can ensure that soils are in the best condition structurally, chemically and biologically. Manure is one of the most important resources that is produced on-farm, and should be valued rather than seen as a waste product. 

A key way to be able to reduce reliance on fertilisers is to develop efficient and effective strategies for managing nutrients and manures on-farm. 

Nutrient management planning

Managing nutrients in a systematic way through planning is a vital aspect of sustainable farming. It is a ‘win-win’ practice which generates advantages across economic and environmental parameters, and allows for the creation of a sustainable agricultural system which is resilient to climatic and economic change. 

Nutrient management planning facilitates optimal use of nutrients from all available sources. Matching inputs of nutrients (from fertilisers and organic manures) to the demand from the crop will allow for an optimal yield, minimise the use of nutrients (which saves costs) and minimises the risk of losses to the environment from nutrients.  

Slurries and solid manures are valuable fertilisers but may also be potential sources of pollution. Within increasing economic and environmental pressures on farm businesses, it makes sense to exploit the fertiliser value of manures while taking action to prevent pollution. 

Most farm assurance schemes require a manure management plan to be completed as part of the certification process. However even without the compulsion of a scheme, having a plan which marks out any environmental features, watercourses, sloping fields which may cause run off and any areas will be a useful resource to consult before applying manures.  

The need for effective manure management

The most effective way of dealing with livestock manures is to apply them at appropriate rates to agricultural land for the benefits of soil and crops. Getting manure management right allows for sustainable use of resources which provides economic savings and reduces the amount of artificial fertiliser that is required. Manures, when stored and applied correctly have fantastic benefits in building resilience within your farming system, cutting costs and lowering your carbon footprint, however if they are applied in too high a quantity or at the wrong time of year then they are an environmental risk. So it is the job of farmers to maximise the benefits that can arise and minimise the risks.

Nutrient management planning to mitigate greenhouse gas emissions

Nitrogen emissions to the air from farms include greenhouse gases, the most potent of which is nitrous oxide. Nitrous oxide is one of the biggest contributions that agriculture makes to climate change. Soil nitrous oxide emissions originate from three sources, soil microorganism activity (55%), organic manure applications (18%) and Nitrogen fertiliser applications, (27%). As such, careful management that maximises the efficiency of any fertiliser applied, takes account soil and climate conditions, and uses the nutrients within manures for crop growth will help to reduce the amount of nitrous oxide lost. 

Nutrient and manure management planning will also help reduce ammonia emissions. While ammonia isn’t a greenhouse gas, it negatively impacts air quality and human health. The amount of ammonia which is lost depends on a variety of factors including manure type, the method and timing of applications, soil pH, the weather conditions at spreading, the soil moisture content and how the manure is stored. As such there are a variety of mitigation options available that are made easy by planning how manure is managed to reduce these risks. 

Soil Testing

Although not always considered as linked to nutrient management planning, monitoring and controlling the pH of soils on-farm is the first step toward good nutrient management. If soil pH is not correct then any nutrients that are applied through fertiliser or manure applications will not be available to the crop and may be lost from the soil incurring costs, reduced yields and pollution issues. 

Effective use of manures – Storage

Having sufficient slurry or manure storage means that effective nutrient management planning is much easier. With sufficient storage capacity, slurries and manures can be applied at the optimal time for plant growth and crop uptake, as well as being applied when the soil and field conditions are right and damage (including compaction and run off) is minimised.  However for some farmers who don’t have enough storage, slurry has to be spread in less than ideal conditions, when there is little crop growth and nutrient uptake. It is in these situations where environmental losses can be the highest. 

Thankfully there are ways that storage can be optimised. This can include minimising the amount of rainfall that is able to enter the store. Rainfall can dilute the nutrient content of the slurry but also costs more in manure application – more water is held within the slurry leading to a higher volume to be spread. Mending guttering, diverting clean water away from stores and covering yards to minimise the amount of water that is entering the store are all low cost ways to help maintain the nutritional value of the manure and also reduce costs. Covering stores is also an option and there are various cover options that are available depending on the store type and design. Floating covers will also reduce the amount of ammonia which is released into the atmosphere which has air quality benefits. 

With solid manure it is important to consider the siting of field heaps and managing the heap to ensure that Nitrate leaching is minimised. Composting of FYM will provide a more stable and uniform material which will have benefits for soil biology, but will not provide such a high readily available Nitrogen source as fresh manure. 

Effective use of manures – Application 

Ensuring that manures are applied at the right rate and the right time is the most important step to reducing environmental risk and improving economic performance of the farm.  The method of application can affect the amount of nitrogen that is available to the crop. Although the total nitrogen content within the manure cannot be altered by the method of application, the proportion of the nitrogen that is available to the growing crops is improved by using low trajectory machinery.

Spreader technology has developed over recent years so that now there are numerous options available for spreading slurry (where losses are potentially higher). Broadcast spreaders will waste nutrients, but this can be minimised by using injection or band spreaders which put the slurry directly on the soil surface or into a narrow slot. For solid manures, the evenness of spreading is far improved by using a rear discharge spreader. If manure or slurry is to be incorporated, ensuring that it is done quickly after application and not just left on the surface where the nutrients may well be lost is important.

Optimising the use of manures and slurries on-farm will provide benefits through improving profitability, resilience and soil health. For more information on manures and nutrient management planning please visit the FCT toolkit pages to access a range of resources.  

FNZ Agronomists’ Workshop – 28th November 2023

Posted on December 14, 2023 by - Farm Net Zero, Uncategorized

This event was designed for agronomists to learn about the results of some of the Farm Net Zero (FNZ) trials. Dr. Hannah Jones of the Farm Carbon Toolkit was joined by the farmers who hosted and designed the trials to discuss the findings. This event was made possible with thanks to the National Lottery Community Fund who fund the Farm Net Zero project.

Throughout the discussions, the new Sustainable Farming Incentive (SFI) payments were referred to as a potential method of reducing the risk of adopting the practices trialled by the Farm Net Zero demo and monitor farms. This report will summarise the trials presented and the discussions that followed, including the views of the agronomists present at the workshop.

Outwintering on Cover Crops

Cover crops can be useful for protecting soil by reducing erosion and nutrient leaching and preserving soil carbon stocks. In Cornwall’s mixed farming systems, cover crops can provide an opportunity for outwintering livestock in a cost-effective manner. Therefore, it is pertinent to think about the plant species included in a cover crop mix and balance up their soil health benefits with the potential feed value.

A Farm Net Zero trial was set up in winter 2021-2022, where five cover crop mixes of varying complexity were grazed by beef youngstock. Full details of the trial can be found on the Farm Net Zero Project Resources page here. The most diverse mix had the biggest improvement in soil quality, reducing compaction and attracting the most earthworms. In terms of feed value, any mixes containing black oats were the most popular with the cattle and had high dry matter, crude protein and sugars.

It was suggested that the SFI SAM2 “Multi-species winter cover” payment of £129/hectare could be used to support this practice.

Maize Establishment

FNZ Monitor Farmers, Malcolm and Catherine Barrett, have trialled different methods of establishing maize crops. In spring 2022, two fields were taken and divided into thirds – one where maize was established conventionally (plough, power harrow, drill), one cultivated with a Sumo machine, and one direct drilled with a Mzuri drill. The direct drill had the lowest fuel requirement and therefore cost. Cob weight assessments found that cobs were smallest in the ploughed area and highest where the crop was established after the cultivator. Soil sampling showed that organic matter levels dropped following ploughing, with worm numbers also reduced.

One further area of interest developed when Malcolm and Catherine noticed that the sprayed-out clover regrew in the direct drilled area. This could potentially provide nitrogen for any following crops, and so a trial was designed for the barley drilled after maize harvest. In this trial, part of the field had no nitrogen applied in order to observe any influences of the clover. Quadrat yield assessments found no significant difference between the full nitrogen fertiliser regime and the no nitrogen area and further analysis of grain nitrogen found that both the full rate and zero nitrogen well exceeded the recommended level for feed barley. This prompted discussions on the opportunities for reducing nitrogen fertiliser (and therefore reducing carbon emissions), with most of the agronomists present agreeing that this is achievable, particularly on mixed farms where livestock contribute to healthy soil. One suggestion from the group was that where soil is in good condition, nitrogen could be applied as a foliar feed direct to the plant because the healthy soil is providing good support for the plant roots.

Soil Rejuvenation after Potatoes

On FNZ Demo Farm, Ennis Barton, some ground is let for vegetable production, when this comes back in hand Andrew Brewer wants to find the fastest method of restoring soil health and returning the fields to cattle grazing. In one of the potato fields, a variety of cover crops (eligible for SAM2) were undersown with ryegrass, clovers and plantain, these were then grazed over winter. Soil quality assessments found that mixes containing Westerwolds ryegrass had the most positive effect on soil aggregate stability. However, in the following summer the Westerwolds rapidly went to seed, which made managing grazing quality a challenge. Therefore, the next best cover mix was forage rape or rye and vetch. This is another example of considering the trade-offs of mixed farming when designing systems that optimise soil quality.

Inter-Crops for Cabbages

Some of the ground rented out at Ennis Barton is used for Savoy cabbages. Following a Farm Net Zero meeting looking at managing these “risky crops”, Andrew and the cabbage growers were keen to develop methods of reducing soil erosion between the cabbage rows. A trial was designed where a mix of low-growing, deep-rooted species (chicory, plantain, white clover and buckwheat) were intersown between the cabbage rows at the beginning of October after all cabbage hoeing was completed. This trial is still being monitored, but there are hopes that intercropping will protect soil from erosion, provide feed for livestock and also reduce the amount of disease/damage to the cabbage leaf from “soil bounce” after rain. Again, this could be eligible for the SAM2 SFI payment.

Grazing Winter Cereals

Grazing winter cereals was a common practice to manage plant disease, growth rates, fertility and livestock wintering. FNZ Monitor Farmer, Anthony Ellis, tried a return to this practice on his family arable and sheep farm during winter 2022-2023. Part of a field of winter wheat was grazed with ewe lambs, with the wheat grazed right into the ground. This allowed Anthony to reduce growth regulators and fungicide and slightly reduce the nitrogen applications compared to the ungrazed remainder of the field. Septoria was reduced early in the season, but there was less difference closer to harvest as the grazed wheat caught up with the ungrazed. Some discussion followed concerning how although this is an old practice, it is now possible to put some firmer figures on the carbon savings of reduced inputs from grazing cereals.

Conclusion

Overall, this workshop for agronomists provided an excellent opportunity to share some of the project’s results so far, and to learn from agronomists who work across the project region and further afield. The ability to work collaboratively with the wider agricultural community is very valuable and helps to ensure the Farm Net Zero project reflects as many farming systems as possible.