Making the most of what you’ve got was a very apt theme for the January arable conference at Greenmount. Presenters talked about organic manures, tyres, cover crops and the use of potash. One English grower talked about the way his farm was evolving and the increasing importance of soil maintenance for farm performance.
Brexit pressures
The annual conference in mid-January was organised by CAFRE, UAS and UFU. In the first presentation, Martin Grantley-Smith from the AHDB talked about Brexit and its possible impact for growers in the UK. He emphasised the importance of current subsidies to profitability and said that his organisation had modelled the potential consequences for the future based on three possible scenarios.
Evolution: An ongoing free trade agreement with the EU.Fitter farming: Tariffs on imports set at zero but support levels cut by 50%.Fortress UK: No trade deal with the EU, WTO tariffs apply and support cut by 75%.The report concluded that the loss of Pillar I support payments would have a much bigger impact than changes to trade agreements and that only the top 25% of farmers would remain viable post-Brexit. Martin said that size is not a buffer to these changes and that performance is the main factor for survival.
He emphasised the need for analytical examination of recent farm performance and for growers to address any weaknesses identified though benchmarking. He said that this is essential because other countries have already developed their route to survival and some of these can deliver this at price levels that make local competitiveness unlikely.
While that previous comment refers to production cost, Martin said that many such countries incur a big additional cost for transport to get their produce to market. The relevance of local provenance to consumers is yet another factor that may affect market value.
He spoke about some international cost comparison work that the AHDB had undertaken. He commented that some wheat growers in Argentina had production costs down to £77/t in a system that targeted 4t/ha average wheat yield. A system that targeted higher yield would result in higher costs and add vulnerability in times of lower prices.
One of the reasons why these costs are low is that growers do not own machinery. They say that if a machine does less than 2,000 hours per annum it should be rented, not owned. Martin also indicated that they estimate a maximum farm size of 10,000 acres, as efficiency falls when farm size gets above this acreage.
The OM legacy
Acting to get the most out of your land was the theme that lay behind most of the presentations at the conference. The use of organic manures on tillage land should show enormous benefits in this regard and this topic had been the subject of a COMS research project in NI in recent years. Dr Ethel White of AFBI led this work and she presented some significant findings from the project.
I would always have said that two of the major benefits from adding organic manures are the yield kicks that result from following crops and the reduced requirement for nitrogen and other nutrients in subsequent years. However, Ethel’s work did not support this, at least not in terms of reduced nitrogen requirement in crops following the specific treatments examined.
Getting results that do not fit popular belief should not surprise us because of the complexity of soil and its inhabitants, Ethel said. Rock, weather and time act to produce and characterise our soils and it is suggested that it takes 500 years of weathering to make one centimetre of soil.
The COMS project looked at the impact of applying pig, cattle, AD digestate or inorganic fertiliser, all at roughly 50kg N/ha, as well as no treatment. One result showed no major yield difference between the treatments, except for the untreated control. The study also showed no evidence of legacy (residual) nutrient to drive the yield of following crops.
The results showed that all the treatments increased nutrient content in the foliage, possibly proportionate to the amount of additional vegetation generated by the different treatments. Treatment with pig slurry generated more vegetative growth and this resulted in the increased offtake of all other nutrients.
Results from other experiments showed that the addition of organic manure (broiler litter) enhanced the performance of additional inorganic fertiliser. She concluded that both forms of fertiliser work better when applied together than when used alone.
Catch crops
Shay Phelan of Teagasc talked about the potential benefits of catch crops to help add life and vitality to tillage soils. Shay said that catch or cover or green manure crops (same principle but different species) might be used for purposes such as:
Nutrient capture through autumn growth.Soil improvement by adding organic matter.Pest control – mustard or radish might be used to help reduce potato cyst nematode numbers.Weed suppression by encouraging and smothering grass weeds. Fertility-building using leguminous species.Animal fodder from edible species.Shay emphasised that the most important thing to decide is why you might want to grow such crops. Fodder equates to one choice while pest control or green manuring would have different mixes. Once the primary purpose is decided, the selection of species falls into place.
All plant families carry benefits and risks. Cereal species are readily available but they risk pest and disease carryover. Brassicas are fast-growing and relatively cheap but they can have other issues such as tall growth and disease carryover to other crops, eg sclerotinia.
Phacelia does not present risks to other crops but seed is expensive and small and so seedbed quality is important.
It needs to be sown early and tends to be easier to incorporate than a mature crop of brassica.
Legumes are useful if sown early as they can leave residual nitrogen for the following crop. But seed can be expensive and they add to the risk of N leaching.
Shay said that early planting is key to maximising benefit as this is largely about bulk. Seedbed quality must be judged relative to the size of the smallest seeds being sown. Successful use of catch crops necessitates early planting. Mixes with very different sized seed can be awkward in terms of sowing depth in a single pass.
The objective must be to have minimal cultivation so as to ensure timely planting for yield. Rolling is essential.
Shay said that longer-term benefits from catch crops include the improvement of soil structure and organic matter resulting in the improved supply of nutrient. Following-crop yield benefits can be small and variable from year to year and site to site. Benefit is heavily influenced by yield and some species, such as rye, can have negative effects on following cereal crops.
Capitalise on K
Looking a little deeper into the soil and crop nutrition, Steve Townsend of Soil First Farming asked if existing soil testing systems are adequate to accurately indicate the supply of nutrients like potash to the plant. Just as the soil itself is a very complex web of ecosystems, Steve said that the nutrient web is equally complex.
Just because a nutrient is present in soil in adequate amounts does not necessarily mean that it is adequately available to the plant. Many nutrients can be the subject of complex chemical interactions which inhibit their availability to feed plants.
Potash, sometimes described as the forgotten nutrient, is a very important catalyst in the plant to help make things happen. Steve said that potash (K) plays a part in the movement of sugars in the plant, air exchange, respiration, water management, the conversion of N into protein, cellulose production and it helps regulate over 40 plant enzymes that are important for growth.
Steve went on to say that it is common to see leaves on plants which show the characteristic white to senesced edges which are symptomatic of K deficiency. These can often be associated with high-K, high-magnesium (Mg) soils where one nutrient interferes with the availability or uptake of the other. Standard soil tests check for what is present in a soil but he said that it is equally important to look for what might be present in excess.
Potash is the single-biggest element used by the plant, Steve said. The quantities required for growth are substantial. Therefore anything that interferes with K availability has the potential to affect growth. Mg is one of the nutrients that can significantly affect K and this can give rise to grass tetany in animals.
Nutrient interaction or lockup like this is commonly associated with the comment that “crops looked very well but they did not yield despite good fertility”. In soils where this is a problem, Steve said that the availability of K needs to be double the level of Mg. In such situations, it is important to apply additional K and this is needed during maximum dry matter accumulation which is at early stem extension.
It is important to remember that K can also tie up Mg or Mg can tie itself up. This can be important because Mg has a relationship with N and Mg is very important for the production of chlorophyll “a”, which is important for photosynthesis. Photosynthetic efficiency is very important in low sunlight regions such as on this island and especially further north and west. Mg deficiency can often be seen in plants as interveinal chlorosis.
Helping prevent these problems depends on more accurate soil testing, Steve said. Knowing the cation exchange capacity of a soil is critical to understanding its nutrient interactions. He said that pH measures hydrogen and it works on the assumption that only calcium affects soil pH. Many nutrients can interact with others and affect their plant availability.
As a final comment, Steve said that blackgrass does not like free calcium but that pH is not a good indicator of calcium supply.
Soil care practitioner
Tom Bradshaw farms 1,600ha in the east of England (250ha owned) in an area of about 570mm annual rainfall. The farm had been a dairy farm but he converted to arable in the late 2000s. The business is mainly winter cereals (wheat and rape) with some livestock. He also has solar panels and an equine enterprise in the farmyard.
Tom is passionate about his soils. Having come from grass, efforts to mind the soil may be less urgent but he is aware that if he allows his soils to deteriorate, recovery is a slow process. He is also a Nuffield scholar and he had examined the growing yield gap between farm and trial yields.
This led him to drive towards sustainable intensification which enabled him to put out higher yield while holding or decreasing his production costs whilst benefiting the environment.
The process forced him to become very conscious of the deep compaction being generated by the ever-increasing size and weight of modern machinery. This thought process forced him to get rid of his big quadtrac and go for smaller power units.
Organic matter is also a high priority and he now acts to maximise the harvesting of sunlight for his crops and his land. Improved soil health has helped to decrease production costs and his fuel usage is now down from 80 to 50 l/ha.
All actions that either decrease costs or increase output must be deemed as essential for farm efficiency in the future.The use of organic manures did not show the expected legacy effect on nitrogen requirement for following crops.Nutrient availability to plant roots may not necessarily equate to its supply in the soil.Catch crops need to be planted early to provide real benefit to the soil and the rotation.
Making the most of what you’ve got was a very apt theme for the January arable conference at Greenmount. Presenters talked about organic manures, tyres, cover crops and the use of potash. One English grower talked about the way his farm was evolving and the increasing importance of soil maintenance for farm performance.
Brexit pressures
The annual conference in mid-January was organised by CAFRE, UAS and UFU. In the first presentation, Martin Grantley-Smith from the AHDB talked about Brexit and its possible impact for growers in the UK. He emphasised the importance of current subsidies to profitability and said that his organisation had modelled the potential consequences for the future based on three possible scenarios.
Evolution: An ongoing free trade agreement with the EU.Fitter farming: Tariffs on imports set at zero but support levels cut by 50%.Fortress UK: No trade deal with the EU, WTO tariffs apply and support cut by 75%.The report concluded that the loss of Pillar I support payments would have a much bigger impact than changes to trade agreements and that only the top 25% of farmers would remain viable post-Brexit. Martin said that size is not a buffer to these changes and that performance is the main factor for survival.
He emphasised the need for analytical examination of recent farm performance and for growers to address any weaknesses identified though benchmarking. He said that this is essential because other countries have already developed their route to survival and some of these can deliver this at price levels that make local competitiveness unlikely.
While that previous comment refers to production cost, Martin said that many such countries incur a big additional cost for transport to get their produce to market. The relevance of local provenance to consumers is yet another factor that may affect market value.
He spoke about some international cost comparison work that the AHDB had undertaken. He commented that some wheat growers in Argentina had production costs down to £77/t in a system that targeted 4t/ha average wheat yield. A system that targeted higher yield would result in higher costs and add vulnerability in times of lower prices.
One of the reasons why these costs are low is that growers do not own machinery. They say that if a machine does less than 2,000 hours per annum it should be rented, not owned. Martin also indicated that they estimate a maximum farm size of 10,000 acres, as efficiency falls when farm size gets above this acreage.
The OM legacy
Acting to get the most out of your land was the theme that lay behind most of the presentations at the conference. The use of organic manures on tillage land should show enormous benefits in this regard and this topic had been the subject of a COMS research project in NI in recent years. Dr Ethel White of AFBI led this work and she presented some significant findings from the project.
I would always have said that two of the major benefits from adding organic manures are the yield kicks that result from following crops and the reduced requirement for nitrogen and other nutrients in subsequent years. However, Ethel’s work did not support this, at least not in terms of reduced nitrogen requirement in crops following the specific treatments examined.
Getting results that do not fit popular belief should not surprise us because of the complexity of soil and its inhabitants, Ethel said. Rock, weather and time act to produce and characterise our soils and it is suggested that it takes 500 years of weathering to make one centimetre of soil.
The COMS project looked at the impact of applying pig, cattle, AD digestate or inorganic fertiliser, all at roughly 50kg N/ha, as well as no treatment. One result showed no major yield difference between the treatments, except for the untreated control. The study also showed no evidence of legacy (residual) nutrient to drive the yield of following crops.
The results showed that all the treatments increased nutrient content in the foliage, possibly proportionate to the amount of additional vegetation generated by the different treatments. Treatment with pig slurry generated more vegetative growth and this resulted in the increased offtake of all other nutrients.
Results from other experiments showed that the addition of organic manure (broiler litter) enhanced the performance of additional inorganic fertiliser. She concluded that both forms of fertiliser work better when applied together than when used alone.
Catch crops
Shay Phelan of Teagasc talked about the potential benefits of catch crops to help add life and vitality to tillage soils. Shay said that catch or cover or green manure crops (same principle but different species) might be used for purposes such as:
Nutrient capture through autumn growth.Soil improvement by adding organic matter.Pest control – mustard or radish might be used to help reduce potato cyst nematode numbers.Weed suppression by encouraging and smothering grass weeds. Fertility-building using leguminous species.Animal fodder from edible species.Shay emphasised that the most important thing to decide is why you might want to grow such crops. Fodder equates to one choice while pest control or green manuring would have different mixes. Once the primary purpose is decided, the selection of species falls into place.
All plant families carry benefits and risks. Cereal species are readily available but they risk pest and disease carryover. Brassicas are fast-growing and relatively cheap but they can have other issues such as tall growth and disease carryover to other crops, eg sclerotinia.
Phacelia does not present risks to other crops but seed is expensive and small and so seedbed quality is important.
It needs to be sown early and tends to be easier to incorporate than a mature crop of brassica.
Legumes are useful if sown early as they can leave residual nitrogen for the following crop. But seed can be expensive and they add to the risk of N leaching.
Shay said that early planting is key to maximising benefit as this is largely about bulk. Seedbed quality must be judged relative to the size of the smallest seeds being sown. Successful use of catch crops necessitates early planting. Mixes with very different sized seed can be awkward in terms of sowing depth in a single pass.
The objective must be to have minimal cultivation so as to ensure timely planting for yield. Rolling is essential.
Shay said that longer-term benefits from catch crops include the improvement of soil structure and organic matter resulting in the improved supply of nutrient. Following-crop yield benefits can be small and variable from year to year and site to site. Benefit is heavily influenced by yield and some species, such as rye, can have negative effects on following cereal crops.
Capitalise on K
Looking a little deeper into the soil and crop nutrition, Steve Townsend of Soil First Farming asked if existing soil testing systems are adequate to accurately indicate the supply of nutrients like potash to the plant. Just as the soil itself is a very complex web of ecosystems, Steve said that the nutrient web is equally complex.
Just because a nutrient is present in soil in adequate amounts does not necessarily mean that it is adequately available to the plant. Many nutrients can be the subject of complex chemical interactions which inhibit their availability to feed plants.
Potash, sometimes described as the forgotten nutrient, is a very important catalyst in the plant to help make things happen. Steve said that potash (K) plays a part in the movement of sugars in the plant, air exchange, respiration, water management, the conversion of N into protein, cellulose production and it helps regulate over 40 plant enzymes that are important for growth.
Steve went on to say that it is common to see leaves on plants which show the characteristic white to senesced edges which are symptomatic of K deficiency. These can often be associated with high-K, high-magnesium (Mg) soils where one nutrient interferes with the availability or uptake of the other. Standard soil tests check for what is present in a soil but he said that it is equally important to look for what might be present in excess.
Potash is the single-biggest element used by the plant, Steve said. The quantities required for growth are substantial. Therefore anything that interferes with K availability has the potential to affect growth. Mg is one of the nutrients that can significantly affect K and this can give rise to grass tetany in animals.
Nutrient interaction or lockup like this is commonly associated with the comment that “crops looked very well but they did not yield despite good fertility”. In soils where this is a problem, Steve said that the availability of K needs to be double the level of Mg. In such situations, it is important to apply additional K and this is needed during maximum dry matter accumulation which is at early stem extension.
It is important to remember that K can also tie up Mg or Mg can tie itself up. This can be important because Mg has a relationship with N and Mg is very important for the production of chlorophyll “a”, which is important for photosynthesis. Photosynthetic efficiency is very important in low sunlight regions such as on this island and especially further north and west. Mg deficiency can often be seen in plants as interveinal chlorosis.
Helping prevent these problems depends on more accurate soil testing, Steve said. Knowing the cation exchange capacity of a soil is critical to understanding its nutrient interactions. He said that pH measures hydrogen and it works on the assumption that only calcium affects soil pH. Many nutrients can interact with others and affect their plant availability.
As a final comment, Steve said that blackgrass does not like free calcium but that pH is not a good indicator of calcium supply.
Soil care practitioner
Tom Bradshaw farms 1,600ha in the east of England (250ha owned) in an area of about 570mm annual rainfall. The farm had been a dairy farm but he converted to arable in the late 2000s. The business is mainly winter cereals (wheat and rape) with some livestock. He also has solar panels and an equine enterprise in the farmyard.
Tom is passionate about his soils. Having come from grass, efforts to mind the soil may be less urgent but he is aware that if he allows his soils to deteriorate, recovery is a slow process. He is also a Nuffield scholar and he had examined the growing yield gap between farm and trial yields.
This led him to drive towards sustainable intensification which enabled him to put out higher yield while holding or decreasing his production costs whilst benefiting the environment.
The process forced him to become very conscious of the deep compaction being generated by the ever-increasing size and weight of modern machinery. This thought process forced him to get rid of his big quadtrac and go for smaller power units.
Organic matter is also a high priority and he now acts to maximise the harvesting of sunlight for his crops and his land. Improved soil health has helped to decrease production costs and his fuel usage is now down from 80 to 50 l/ha.
All actions that either decrease costs or increase output must be deemed as essential for farm efficiency in the future.The use of organic manures did not show the expected legacy effect on nitrogen requirement for following crops.Nutrient availability to plant roots may not necessarily equate to its supply in the soil.Catch crops need to be planted early to provide real benefit to the soil and the rotation. 
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