Fertility break

[Hornet]

What would be the merits of a mob grazed, one or two year fertility break? Would be interested in the value of that for:

1. A livestock farmer in terms of what rent would be fair to have access to summer grazing or even silage?

2. Value in next crop margin to an arable grower as opposed to a break crop such as linseed or beans (assuming fixed costs are paid for per operation so lowering of FC's achievable)

 

[Brisel]

This would be good question to ask in the Direct Drilling sections. There is a very long thread on mob grazing in there.

I'm running a mob grazing trial here looking at this, based on external reusable Clipex fencing and a radial arrangement of electric fence paddocks around a central water bowser. The plan is to leave the ley down for 6 years (6 year rotation here). The trouble with short leys is the establishment cost of the grass. Spreading this over a longer period really reduces the cost per year then you've go the not inconsiderable cost of fencing and water infrastructure for grazing.

1. What are grazing rents in your area? New leys are more attractive for silage which helps the location but your soil benefits will be lower unless biomass offtake is covered by manure in return. I don't know how compatible this is with the proper mob grazing concept that is much better for soil health.
2. This depends on grassland pests like wireworm attacking your following crop or what weed issues you had before. Quantifying a 1% increase in soil organic matter in terms of yield is also tricky. Ryegrass leys strip potash out of the soil and are not a true take all break. My first wheat after a 1 year Westerwolds silage ley was 1 t/ha less than wheat after osr and needed Dursban thanks to frit fly. Those fields now have a IRG/Westerwolds volunteer problem, so it's not necessarily all a good thing.

 

[Hornet]

This would be good question to ask in the Direct Drilling sections. There is a very long thread on mob grazing in there.

I'm running a mob grazing trial here looking at this, based on external reusable Clipex fencing and a radial arrangement of electric fence paddocks around a central water bowser. The plan is to leave the ley down for 6 years (6 year rotation here). The trouble with short leys is the establishment cost of the grass. Spreading this over a longer period really reduces the cost per year then you've go the not inconsiderable cost of fencing and water infrastructure for grazing.

1. What are grazing rents in your area? New leys are more attractive for silage which helps the location but your soil benefits will be lower unless biomass offtake is covered by manure in return. I don't know how compatible this is with the proper mob grazing concept that is much better for soil health.
2. This depends on grassland pests like wireworm attacking your following crop or what weed issues you had before. Quantifying a 1% increase in soil organic matter in terms of yield is also tricky. Ryegrass leys strip potash out of the soil and are not a true take all break. My first wheat after a 1 year Westerwolds silage ley was 1 t/ha less than wheat after osr and needed Dursban thanks to frit fly. Those fields now have a IRG/Westerwolds volunteer problem, so it's not necessarily all a good thing.

Thats very interesting, and the crux of weather this is feasible or not; as a gross margin of linseed beans or even a poor, flea beetle damaged rape crop less contracting costs doesn't add up unless you include the yield increase to the next cereal crop.

So the solution? fallow ++ ie fallow with a cover crop and livestock grazing. Minimal VC's: and FC's but with the benefit of all the things a normal break crop would bring plus more OM?

Yes short leys are a problem in terms of establishment and seed costs, but thinking very much as a one or 2 year break crop with an organic matter / manure return hopefully increasing fertility better than a break crop. Would grazing rent cover seed, DD establishment and "temporary" electric mob fencing" costs? Not sure what grazing rents for suffolk would be... £100/ha? Forgive me if I'm talking twaddle (I am an arable man after all!)

Would like to think that a ley with manure from grazing would be as good as an application of compost in terms of soil benefits? In terms of pest problems I'm sure leatherjackets, wireworm etc would be a problem if the ley was down for more than a year!

Weeds: the blackgrass problem in East Anglia going into the future is going to become even more of an issue (by the look of whats happening round here) and I want to be proacive on my approach to its control before it gets unmanageable.

Would a species rich "herbal ley" (clovers etc) be of advantage to livestock and then deserve a better rent, the land would gain from N fixation also, and manure return would help mitigate P and K losses.

 

[hindmaist]

A six year ley on a six year rotation? It's going to take a generation to get round the place.

 

[franklin]

Dont underestimate the value of grass as a fallow instead of beans for greening.

So,

2yr ley. But in reality, farmer keeps it there for three years with the last year being for greening fallow. First two years stock man cuts / grazes as they like. After 1st year work out P&K taken off, and stock man then spreads twice that on as muck. Hence arable man does not loose indicies. First two years are hence working the land hard. Third year arable man gets greening without land going sad. Then you crack on blacking it over for OSR. The savings for a well established crop of OSR after a three year grass break are going to be good. Then wheat, spring barley or whatever, and back to grass.