Most cost effective way to build soil carbon

But you have to be able to get the cover crops established, every year for this to be a reliable way of building carbon / soil health. and you still get a time of the year when there is the most solar radiation about when either the cash crop is dieing and not pumping carbohydrates into the soil, or the cover crop is still very small and not really collecting much sunlight. I recon that Andy Howards work on companion cropping might well be able to deal with these issues though.

martian said:

I regret not testing som before putting this herbal ley in, but soil is completely diifferent after 3 years and amazing amount of plant growthView attachment 371064interested to know whether chicory acts like litmus paper. One in foreground is pink whilst most are blue. Any ideas?

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Just don't let the chicory seed !

jondear said:

Just don't let the chicory seed !

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Will it keep coming up for years?

IEM said:

This is where the cost effectiveness questions come in for me. I love the idea of mob grazing herbal leys BUT I have stocked 18 ewes + 28 lambs/ha on a low input grass/clover ley this year which means the sheep are stocked heavily enough to pay their way compared to any arable crop AND they will certainly be improving soil.
Probably the improvements would be bigger if I used a herbal ley but if stocking density is reduced to 10 or 11 ewes + lambs per hectare are the additional benefits worth it? Or should I import more compost with the additional profits from sheep?

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Like I say I'm not really pushing anything at the moment, You could probably get more out of what I've got I know Rob Richman has his dairy cows at 2 LSU's/ ha that might well be closer to what you are at. I guess there's also the reported reduction in vet and med costs, but I think you could get most of them from rotational grazing anyway. Plus you don't have to have a herbal ley to mob graze you could happily use what you have.

IEM said:

Looking very good. I have a more conventional 3 year grass clover ley which has been rotationally grazed by sheep in which the soil is also greatly improved. This year I am sowing a mix closer to a herbal ley with red clovers and festuloliums added and will have a longer grazing rotation so we will see how that goes. Do you plan to direct drill an arable crop at the end of the ley?

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Yes, planning on drilling winter beans next autumn, as wireworm and grass weeds will make wheat tricky first spot in rotation, but I keep changing my mind and by this time next year who knows what happy ideas will have floated in my head.. Imust say I've been really impressed by the amount of grazing the herbal leys have provided and we've left a lot of litter behind with each pass to protect and feed the soil.

IEM said:

Yep it's all exciting stuff and definitely think all 3 soil improvement methods currently used are beneficial in their own way just struggling to grasp which one is most worthy of increasing. Maybe I should be doing more of all 3, it's just making sure they are paying their way. Compost is the easiest to cost and the most expensive per hectare but it is also adding a lot of p and k as well the value of which cover a good chunk of hauling/spreading

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I think that a little bit of everything has to be the right idea, Some of these you won't really know if they are paying their way for a few years, so just do a little bit, as much as you can stomach financially and do get to hung up on what the best return might be. If you can record your costings do that then in 5 years time you can look back and decide which was best, but in reality you will have moved on to something else by then, probably a hybrid of these ideas. The most important thing is to start doing something. I'm not sure how important P and K will be as you progress along this route though as I think you might find that the Biology will start to make more of what you already have more available.

Interestingly we had 2 girls from Rothamsted round today and they were saying that when soil carbon drops below a certain level then it is very hard to bring it up again. They applied FYM 4 years running on a low carbon soil and it didn't add any measurable SOM to the soil...

No I'm not really into measuring to be honest. I do have some albrech tests done before we started and I could do some after. I know that from the work the wildlife trust have done that we have 4 times more worms on the grass land than the no till crop land in 3 years. And that I found Nodules on the red clover roots 1.2 meters down in a soil pit. which suggests that air must be getting down that far. I'd imagine that if I did water infiltration tests I'd be pleasantly surprised. And a crop of spring barley I grew after. 2 years of red clover and rye grass looks promising, really thick stems with no purpleling at the bottom. And I get to spend less time worrying about the weather because when it rains the grass is growing and when its sunny we can harvest.

IEM, For many years I have followed Robert Elliott (Clifton Farm) in believing that four years ley and four years cropping is the ideal rotation. I quote:-

I think there will be very few people who will dispute that proper use of the land means maintaining an OM content of a few percentage points and that means using organic manures, but unfortunately they take time to produce, and it is extremely difficult, in fact normally impossible, to produce as much as you need. It also takes perhaps more years than you have available to build up depleted land from a starting point of only 1 to 2% OM in the soil to my own, totally scientifically unfounded opinion of a moderate level, and that is a minimum of 5%

I have seen a suggestion from Washington State University in the U.S. that 5% is adequate. Given that you cannot be certain how quickly it is being used up, and wanting to avoid testing every year, I am inclined to go for a wee bit more if possible. The figure of 2% is often given as an absolute minimum and I remember being told once upon a time that below 1% and your soil is dead.

The worst test I have had was one of 1.3% in a mature olive grove in Portugal that had not received any input of soil nutrients for an unknown number of years. I have also seen it stated that there is no scientific evidence that 2% is a meaningful benchmark, but on the basis that some is necessary this figure is perhaps the best guideline and urgent action should be taken if a figure of less than 2% is obtained on analysis, whilst if it is 5% or more it is one less thing you need to worry about.

Certainly the area with only 1.3% on the Portuguese property proved to be a very difficult piece of ground. It had the appearance of a decent sandy loam when freshly cultivated, but like the rest of the place containing many stones. The topography suggests that it was the bed of the adjoining river away back in the dim and distant past, and the stones are water worn. It set very hard after rain or irrigation, water filtration and retention were extremely poor. Some weeds grew on it, but not in profusion, and very few different species. All in all the typical symptoms of a soil that lacks OM.

The major part of it was in pasture for 4 years and grazed as frequently as possible with well-fed stock in order to increase the organic and soil nutrients content. It is now totally changed in character and is as good as it looks. The OM increased to 4.5% during these four years.

It is appropriate to note that during the time this particularly low OM content land was in pasture, I grew eight consecutive green manure crops on the land where we planted the other new olive grove of 299 trees, and the OM increased by only 0.3% from 2.7 to 3. These crops were well fertilised, well grown and cultivated into the soil.

that all sounds like a sound plan, Listening to a gabe brown interview yesterday I think I wouldn't bother measuring OM, and instead go for water infiltration. Mainly because you can do that on farm cheaply and quickly, and you will struggle to have one without the other.

Depends how many generations you are prepared to wait

"results show that when Miscanthus is grown on land previously under arable agriculture, the soil organic C will increase to a level above that of native pasture, as Miscanthus organic material is shown to have a slow decomposition rate"

Taken from http://onlinelibrary.wiley.com/doi/10.1111/j.1757-1707.2010.01033.x/full

IEM, I think the only thing you have misssed is reading Robert Elliott's book. His grass seed mixes were very complicated though and I think not necessary, but I accept he was far more knowledgeable than me about such things. Sir George Stapleton thought they were complicated too, so I am not alone.

My quote of my own writing (at #36) showed an increase of OM from 1.3 to 4.5% in only four years so you will not have long to wait. I did have some Puna chicory in the mix but not plantain. It was basically perennial ryegrass (forget the variety without checking records) and Haifa white clover, which I had successfully used in Australia. It was sown in late 2005 and after cultivating it out the 2010 test showed the 4.5% OM. It still tested 4.5% in 2014 but with higher pH and elevated P and K levels. It had been planted to olives in the spring of 2011, so no further grazing, but well fertilised. I do a simple NPK, pH and OM content test on all fields every 4 years. I also do a more detailed leaf analysis of trees if I feel it is appropriate. The trees will soon reach the size where sheep grazing can be permitted, but not goats for quite a few years - if ever. They eat everything in reach and that is more than 6 feet from the ground.

If you are using leys and then some cropping I do not see the need to apply compost to grassland - or perhaps I am misreading you, and you intend to apply the compost to land in the cropping phase as Elliott did? I relied on a small amount of concentrates fed to the goats at housing each night to provide some of the trace elements in their droppings, and the lime and most of the fertilisers I use have a good range of trace elements in them. N.B. Housing of small livestock at night is essential because of the number of large dogs that wander about, sometimes in small packs.

I have never grown Miscanthus, but did consider it on a couple of occasions and decided against it. I agree with what Courier posted. Plenty of undecomposed OM, a bit like maize I suppose, but it takes a long time before that OM becomes available to your following crops. I still find the crown and thicker pieces of the stems of maize several years after having last grown it in four fields.