Pasture Cropping + Biochar. A marriage made in heaven?

[Michaelangelica]

Pasture Cropping + Biochar. A marriage made in heaven?

This is a programme on Pasture Cropping.
The idea of sowing your crop directly into unploughed fields full of grasses.
The object is to increase soil organic carbon.

Again, another counter-intuitive idea as for Biochar/ Terra Preta--"burning" things to reduce greenhouse gasses.
Won't the grass take away water and soil nutrients from the crop?
Quite the opposite say the proselytisers of this idea.

But what if you sell your carbon for credits and you let your soil carbon fall? Do you have to pay your carbon credits back?
Good question; but will that happen if you spread char on the soil at the same time as sowing?

It seems to me Biochar works best in soil with high levels of organic carbon.
This looks to me like a marriage made in heaven.

Quite along video, but well worth the time looking at it, if you are a farmer or interested in solutions to Global Warming. It is intersting that mining companies like Rio Tinto and The Qld. DPI are helping fund some research.

ANNE KRUGER, PRESENTER: There's a great deal of unease across rural Australia about the cost farmers will bear when agriculture is eventually included in an emissions trading scheme. For every carbon credit, such as planting trees and leaving pasture intact, there's a debit, the cost of using fuel, fertiliser and other farm chemicals. While it's fair to say soil-carbon sceptics still outnumber supporters, one scientist claims it's the key to farming profitably in a carbon economy.
PIP COURTNEY: What keeps you going?

CHRISTINE JONES: A belief that it will work. Yeah... I, absolutely, at a very deep level, I fundamentally believe and I actually know at a deep level that it does work.

PIP COURTNEY: Christine Jones's message is simple:

CHRISTINE JONES: Rebuilding carbon-rich agricultural soils is the only real productive permanent solution to taking excess carbon dioxide from the atmosphere.

I feel the same about terra preta gardening/farming
Video at:-
http://www.abc.net.au/landline/content/ ... 490568.htm

[janahn]

pasture cropping is ideal in semi arid regions, say Moree, norther central NSW, in pastoral country that is lightly stocked. Winter wheat/barley is planted in the same manner as no till farming. Native grasses do not grow in winter. Wheat and barley are winter crops in Australia. A place like Moree has reliable winter rain. Heavy soils store good reserves of sub soil moisture. Self mulching alluvial black soils are best as they are not so prone to compaction from grazing if managed well. Leo Mahon

[MonteGoulding]

Can someone explain the technique, do you just spread the seed and hope the birds don't come in or do you make seedballs? I'd like to run an experiment this winter if I understand the technique.

Cheers

Monte

[janahn]

You may broadcast seed in may-june-july, say oats wheat barley, when it rains, ideally for an extended period, say a week of drizzle rain is ideal, and these seeds will strike. or as in no till farming, the soil is only disturbed when you plant the seed with a drill. small scale that may be a pick that scaldes a line, say 2 inches deep, sprinkle seed in and cover over. seed rates vary, but not too thick, maybe 20 wheat seeds per linear metre. Leo Mahon

[ppp]

I have never heard of the seed just being spread along the top. If the ground is soft enough for the seed to sink into the soil, it will definitely too soft for a tractor to pass over it.

An air seeder such as this :http://www.watsonfarmmach.com.au/airseed.htm is used, it allows the seed to be planted (under soil) without heavy plowing or removing existing vegetation.

[janahn]

hi ppp, during the bumper wheat crop of 1978, some farmers who couldnt get on the land for planting, (it was too wet) they arial sowed from aeroplanes . it is a well know technique amongst farmers. it is how i propogate saltbush seed as well. leo. keep it wet and it will grow

ps; bingo. the same technique as no till farming. you have got it. same as the air seeder you have refered to above

[zzsstt]

The original idea behind pasture cropping, the way it was explained to me (much of the development of the system was done in my area), was to maximise profit rather than yield. Conventional winter cropping uses high levels of inputs, normally with a summer fallow maintained by chemicals or tillage, and targets the highest possible yield. With pasture cropping, perennial native grasses are grazed through the summer, thus both giving a financial return and maintaining ground cover to reduce erosion, weed invasion etc. In the autumn, when the native grasses go dormant, livestock are excluded and the paddock is sprayed with a low rate of RoundUp to kill any annuals weeds. It is then direct drilled with a reduced rate of cereal and fertiliser, which is managed in much the same way as a conventional crop. After harvesting, the native grasses regrow for the following summer and the cycle is repeated.

By reducing inputs the financial costs are reduced below those of conventional cropping. There is also the potential to build organic matter, store carbon, reduce weed levels, reduce erosion by maintaining ground cover etc. The yield reduction against conventional cropping which results from lower inputs, lower stored moisture etc. is theoretically more than offset by the lower input costs, and therefore the entire system (including grazing) becomes finanically more profitable.

A a couple of caveats; It requires a "good" base of established, locally adapted summer native perennial grass pasture. It will not work well with annual grasses, winter grasses or heavy weed levels (summer or winter).

Aerial sowing is most often used for low rate "additions" to existing systems, such as subclover into native grasses, where a large area can be covered quickly with a relatively light payload. Where a high sowing rate is used (cereals can be sown at 100kg/ha or more, though normally at perhaps 60 to 80kg/ha, plus fertiliser at 80 to 100kg/ha), aerial sowing becomes very expensive. It also produces are far less even application, which is fine for adding clover but less good for cereals. As the seed remains on the surface, germination is greatly reduced, and seed theft by birds, ants etc is increased. I cannot believe it would be viable to aerial sow cereals in our current market.

Seed broadcast by any means (aerial or ground based) has reduced germination rates and increased theft, which is why seed is normally "drilled". A direct drill will cut a slot in the soil perhaps 100mm deep. It will then partially refill the slot with loose soil, then deposit seed and fertiliser on that loose soil. Finally it will cover the seed and lightly compact the soil above to improve seed to soil contact, thus providing the best conditions for germination. This is, obviously, exactly what a gardener does when sowing vegetable seeds, but on a vastly increased scale. Other techniques of sowing, such as simply broadcasting, or broadcasting followed by harrowing to (hopefully) cover the seeds, are ALWAYS less successful, and require a higher sowing rate to counter the reduced efficiency. Depending on soil type and conditions, and exisiting groundcover, they may not work at all - hard, bare soil will result in almost no germination.

The phrase "air seeder" refers simply to the mechanism used to move the seed and fertiliser from the bin to the sowing points/knives/discs, i.e. a large fan that blows the products along a series of pipes. The actual sowing device used on an air seeder can be conventional (requiring a seedbed prepared earlier by ploughing and harrowing), or a direct drill which requires no previous "workings" of the soil.

Direct drilling and "no-till" farming are the same thing by different names. Many years ago the same technique was called "sod seeding".