Agroforestry with Kellogg's

Agroforestry Oats and Fruit Trees

My introduction to Agroforestry was a great experience and one that has opened up my eyes to viewing farmland in a very different way.  As part of the Kellogg’s origins group (link) we were very lucky to be given a tour of the Agroforestry enterprise at Blue Bell farms, by Steven Briggs.  Steven farms as an organic farming tenant growing wheat, oats, and some vegetables on some very good soil near Peterborough.

The 125 acres of agroforestry is laid out across six fields in 3m bands of fruit trees separated by 24m of cropped land.  The trees are on shortish, root stocks so the fruit can be picked, and the fruit trees pruned by hand and so that the roots don't get deep enough to interfere with the land drains.

Agroforestry Fruit Trees

The system looks at the land in a 3D way.  The trees are able to put roots down below the crop root zone to capture nutrients and moisture lower down in the soil profile. Most arable crops root between 1-2m whereas the trees go down to 10m so there's little competition for these plant essentials.  The tree divisions increase the crop edge effect and the leaf mulch falls onto the cropland, returning nutrients as they decompose.  The trees also act as a wind-break; for every 1’ of tree height you get a 10’ wind reduction effect, very important in the flat fen lands.  This reduction in wind also reduces the notorious ‘fen blow’ of topsoil across the fields and enables more spray days.  Spray days on an organic farm you ask?  Steven's soil is short of manganese so regular applications are applied to supplement the soils deficiency to the growing crops.

Ploughing Overwintered Stubble

The strips that the trees are planted on can be planted with pollen and nectar so that in the short term will provide brilliant insect habitat.  Overtime these will turn into brilliant beetle banks providing habitat and food for beneficial insects helping control pests.  The system is run with a 6m Controlled Traffic Farming layout to keep machinery wheelings running in the same place, except where the overwintered stubbles are ploughed.

So are there any down sides?  To be honest there we’re too many. Yes it ties up the land for a long period of time as you need to write down the cost of the trees, so OK if you own the land but difficult if you are a tenant and a 3 year FBT makes this impossible.  There is a large capital cost, even planning at 120 trees/Ha.  Over time the yield from the crops reduce as the yield from the trees take over but if you have a market for the fruit then the output is significant.  It makes a lot of sense.

Everyone who visited was really impressed with the system and it certainly made everyone think a little more about some of these techniques could be employed on their own farms.

Glyphosate - A Key Ingredient

Over-winter Ploughed field

Not that long ago, the land at Overbury would have been ploughed over the winter time to prepare it for the next crop.  This is a destructive process for all of the organisms; bacteria, nematodes, fungi and earthworms that live in the soil.  It was the only way farmers had to control weeds and create a seedbed suitable for our equipment to plant the seeds into.   Many fields destined to be planted in the spring would have been left in this ploughed state over the winter period.  We now know that is method of land preparation; and we are catching up with the rest of the world, is a very bad practice for many reasons.

The most significant reason is that we are adding air to the soil, which reacts with the carbon locked in the soil, releasing Carbon Dioxide (CO2) into the atmosphere, a significant ingredient in global warming, adding to the changing climate threat.  The tractors that we use release Nitrous oxide as they burn the diesel, (just like diesel cars) and ploughing uses a lot of diesel.  Moving the soil also destroys its structure, meaning that small particles of silt, are washed through the soil taking pesticides and fertiliser with them.  They wash down to the depth of the cultivation and fill in the pores resulting in the surface level water logging.  This water logging means that any subsequent rain can't infiltrate into the soil and so runs off causing surface erosion. Soil erosion can be reduced by 90% buy not cultivating and using Conservation Agriculture techniques. The soil particles end up in the streams and water courses silting up the stream beds, reducing water flow capacity and can potentially lead to flooding further down stream.  

There are the soil inhabitants to consider as well.  Cultivation destroys their habitat and their food supply and we need them to help our plants (and therefore our food), to collect nutrients from the soil.  Worm populations can be reduced by 50% by ploughing.  We need the worms to aerate the soil, digest the soil and restructure it, adding glomalins (glue) to stick the particles together and recycle dead and decaying plant materials.  A healthy soil is one that can sustain itself with as little human interference as possible and that means not cultivating.

A field after winter with cover crops

Soil is also greatly improved by keeping it covered, using plant material or previous plant residue, a theory nicknamed 'soil armour' in the U.S. This concept uses plants to intercept rain droplets, keeping the soil surface open and aerated.  The plants in the picture above have been growing all winter, capturing available nutrients, taking carbon from the atmosphere and locking it up in the organic matter of the plant, restructuring the soil, feeding our soil biology and providing a brilliant habitat for birds and mammals, Our cover crops this year have hosted brown hares, starling, redwing, field fare, lapwing, meadow pipets, yellow hammer, chaffinch, linnets, snipe, woodcock and many others across these fields.  Compare that to the ploughed field above where it is mainly lifeless.

From the environments point of view cultivation's are not a good idea.

So why the long blog about protecting the soil?  Well this method of farming, called no-till or zero-till, is under threat from misinformed lobby groups trying to get the active ingredient 'glyphosate' banned from all of our European crop production systems.  It is a very safe herbicide, (weedkiller) that we use instead of cultivation to kill weeds and cover crops, prior to planting our next crop.  It has been a valuable tool available to farmers for the last 40 years. Without glyphostate there will be serious implications to our food security and the negative effects of cultivation, (listed above) in terms of mechanical weed control will return.  It is used across the world and is one of the most rigorously tested of any pesticide, that is currently registered for use.  An EFSA (European Food Safety Authority), concluded in a peer reviewed report (published EFSA Journal 2015;13(11):4302in) 

"glyphosate is unlikely to pose a carcinogenic hazard to humans and the evidence does not support classification with regard to its carcinogenic potential".

The only body to conclude that glyphostate might pose a health risk is the IARC (International Agency for Research on Cancer) who concluded it is "probably carcinogenic to humans".  According to the IARC's own classifications glyphostate is in the same category as drinking very hot drinks, working as a hairdresser and working night-shifts.  Glyphostate is safer than orange juice, bacon and indeed coffee, so we need to keep it in perspective and look at the benefits it delivers in globally feedin the world.

Without glyphostate, as part of an Integrated Farm Management approach  UK yields of wheat and oilseed rape (canola) will drop by about 20%, primarily due to weed competition.  We will need to use 546,000 Ha more land to replace this lost production.  Our farms will not be able to compete with other growers using it around the world. Profitability would fall and cheap food imports will be sucked into the country; in many cases produced to lower environmental standards. Mechanised weed control, including ploughing will return; reducing our soil organic matter, biological life, disruption to ground nesting birds and fewer environmental benefits. It will be a gloomy picture.  

We need to look at the whole system to appreciate how decisions impact on each other and if the cause and effect can be beneficial or not.  Nothing is simple or black and white.  I know that not being able to use this proven, safe chemical will impact severely on what we do and how we do it; eroding the positive environmental benefits of no-till farming.

No-till planting Into Cover Crops

The 5 Minute Fallow

The 5 Minute Fallow

Well after 2 years of trialling and testing, of calculating and studying our Cross Slot drill has finally arrived, imported all the way form New Zealand.  I say finally arrived, it actually arrived in July 2015 but shamefully I have neglected my blog, so here's an update on my latest thinking and plans.

The 5 minute fallow is the first place to start.  The picture above shows the drill planting a cover crop mix directly behind the combine.  Why are we doing this, I hear you ask?  The cover crop plants will stay in the ground after the oilseed rape has been harvested and before we plant wheat in the same field.  The job of the cover crop is to:

Cover Crop at 4 weeks old

1. Intercept the sunlight during the period of maximum radiation and turn that sunlight into roots, shoots and leaves.  This plant material will have several benefits to the new zero tillage farming system we are adopting.  The roots will penetrate down in to the soil breaking up soil compaction, create drainage channels (when they die) and release sugars in the soil to feed the soil fungi and bacteria, which in turn feed earthworms.
2. The leaves and stems of the plants will store nutrients that might otherwise leak or escape from the soil which could create pollution.  Things like sulphate and nitrate are very soluble in water  but non-mobile when part of a plant.
3. Create soil armour.  August has always been the farms wettest month, with heavy thundery summer storms hammering down on the soil surface.  By having a protective shield on the surface, in the form of leaves, the rainfall is intercepted and can infiltrate at a faster rate, with reduced micro compaction on the surface.
4. When the cover crop is destroyed the dead material will slowly turn into organic matter (OM) which can hold greater amounts of nutrients and water than mineral particles.  OM can potentially hold 10x more water than the mineral soil alone.  Few arable soils in the UK or around the world have OM levels greater than 5%, which is where it needs to be as a minimum.  The OM will help to feed the soil bacteria and fungi which in turn will help to feed our crops.
5. Reduce weeds in the seed bank, as some of the seeds will be germinated when the cover crop is planted which will be destroyed with the cover crop.

After the cover crop comes the main crop in the case of the field below, wheat. This picture was taken at the end of October when the crop was about 4 weeks old and shows good even plant establishment with little sign of pest (slug) activity.  The crop, if anything, is a little too thick.  

Wheat Planted after Cover Crop

A cover crop is not a "fix all problems in the field from a bag, rather than a chemical container" but it does have a lot of advantages when it comes to improving the soil health and workability of the soil.  It will contribute to increasing OM levels and it will create drainage channels to improve water infiltration into the soil, key when reducing soil erosion and storing more water in the fields, and can help reduce flooding down-stream.  We use cover crops to reduce the exposure of our soils to the elements of wind, sun and water; all of which have massive long term benefits.  I will be back with a follow up blog on dealing with cover crops and getting the next crop established through increased levels of crop residue.

Interest In Cover Cropping

In the run up to Christmas I hosted almost 100 farmers on three different visits to look at the Cover Crop trials that we planted back in August and September.  The seed was generously supplied by Kings and used in a trial to look at the benefits and costs of using cover crops in the farm rotation. Cover crops have only recently come to my attention through my Nuffield Farming Scholarship Trust award to look at increasing wheat yields n the UK.  Although we have been using turnips and forage rape for years as a sheep feed through the winter period, there is so much more a cover crop can deliver other than feeding ewes or lambs through the winter.  The cover crop idea has also sprung into life as they can count towards Ecological Focus Areas (EFA's) in the the new Common Agricultural Policy.  In total we have planted 11 different mixes or single variety species to see what benefits or negative effects can be measured..

Paul Brown (above) from Kings, demonstrating the tap rooting ability of radishes to push down into the soil to break up compaction caused by farm machinery.  The ability of all of the mixes to scavenge for nitrogen and phosphate that would otherwise be lost from the field is tremendous, and if your include vetches into the mix their ability to fix nitrogen form the atmosphere is staggering.  The plot of straight vetch analysed at over 30% protein and was holding over 200Kg/Ha of nitrogen that will be available for the following crop!  Species in the various mixes included, mustard, forage rye, vetch, radish, oat, berseem clover, phacelia, buckwheat and linseed.  The mixes have been assessed by NIAB as part of our Kellogg's Origins Group, looking at ways in which we can farm in a more environmentally and financially sustainable way.

The crops certainly tick all of those boxes by: intercepting sunlight through the autumn and winter, turning it into carbon (plant matter) to improve soil organic matter levels (when decomposing); help remove compaction by aggressive rooting; locking up nutrients that would otherwise be washed through the soil into the environment; provide valuable late season pollen and nectar sources (bees using ours until November), provide a nutritious balanced diet for overwintering stock: stabilise and protect the soil surface from heavy rainfall events.  It is almost all positive effects form these crops bar the creation of a lovely slug habitat.  This will need watching and monitoring through the winter and into the drilling period to keep on top of the slippery problem!

Day 8 - Time for a Tour of the District

Our host Alec Wright; Nuffield Scholar, in Methven graciously showed us around the district this morning visiting his sons farm first thing to drop off some lunch made by Jean, Alec's wife. We looked at the silage operation before moving up to some higher and stony ground to look at some direct drilled grass reseed.  This field was coming up beautifully due to the reduced disturbance retaining moisture win the soil.  There is no luxury of irrigation this far up the slopes on Mt Hutt. The swedes were also direct drilled into grass stubble that had been sprayed off and were emerging well on the whole although as temperatures reached 29 degrees today and with a stiff breeze soil moisture was paramount.  This would also go for wheat production.  A single cultivation will reduce the soils water holding capacity by 25mm, which could be important later on in the season.

If cultivated and a North Westerly gale blows, the wind is funnelled down through the mountains and the soil will be eroded by the wind, leaving the field and being caught up by the nearest obstacle, in this case a small hedge.  The depth of this top soil was 2 ' deep and seeing this brought back thoughts of the great dust storms of the 1930's and my time in Oklahoma.

The wind can also do some serious damage to the infrastructure of the farms when really unleashed.  Earlier this year about 800 irrigators were blown over during winds that reached 200Km/hr in places. This is putting huge pressure on the mechanics required to repair all this damage but without water there are no crops or grass.  Production in some areas has fallen away simply because there is no water to keep the crops alive.

We drove passed one terrific looking crop of wheat being irrigated.  The plant population was thinner than our UK target but the plants had tillered out very well.  The stems and upper leaves were clean of disease and the potential of thigh yield was definitely present.  I think  this picture sums up the advantage that New Zealand has over the UK when it comes to wheat production.  It seems that an abundance of water, (for the time being), and lots of sunshine are the key ingredients to very high yields.  But the plants need to be fed correctly and the soil has to have the correct structure to support root development that will enable faster, less restricted uptake of nutrients. 

This is where crops like this fodder radish can help in restructuring the soil.  The tap root, along with the other 30/m2, are all pushing down through the soil profile, finding a way through any compacted layers in search of water and nutrients.  The field had a good population of plants all creating drainage for water infiltration, for when it does rain, and removing any compaction layers.  The obvious next step would be to direct drill the next crop to reduce the erosion risk; as evident above, reduce cost of establishment and increase the amount of water available to the following crop.  By not tilling; the soil will increase it's organic matter content allowing further increases in the water holding capacity.  Seems to me like a good way to progress?