Zero-Till Brazil: Saving Climate One Furrow At A Time
by John Laumer, Philadelphia on 02.15.07
Per a story in SciDev.Net, Brazilian farmers are foremost in the world with use of Zero Tillage, a cropping method that is greener, boosts productivity, and helps the climate. “Called direct drilling, no-tillage or zero tillage (ZT), the technique is in part praised for fixing carbon in the soil, thereby reducing the amount of carbon dioxide — a greenhouse gas — released into the air. It also prevents soil erosion and therefore demands less irrigation”. Because this story is complex, we highly recommend the entire article, which is posted here. In general, the practice of zero tillage agriculture reduces erosion, partitions water into groundwater instead of runoff, increases the organic content of soil, and helps fix more carbon in it.
From the SciDev article:- "With the best systems you have over a ton of carbon sequestered [in the soil] per hectare per year. When you consider there are a hundred million hectares under ZT in the world, this is an awful lot of carbon dioxide taken out of the atmosphere," says British agronomist John Landers, who has promoted the technology in Brazil since the 1970s".
And of course the devil is in the details. For optimal zero-tillage effect, certain croping systems will require the application of glyphosate, so that weeds won’t out-compete the food crops. Just think on that: Monsanto might turn out to be an accidental climate savior.
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Apart from the specialised machines required, there don't seem to be any downsides to zero-till! I'm guessing it must be less productive. Or surely everyone would do it?
Growing up on a farm I can say that there is really no difference between crops planted via no-till. The downsides are lack of soil aeration over time, typically farmers must apply a liquid fertilizer when planting and also an herbicide. It is beneficial in situations where soil erosion are a problem and where cultivation is particularly difficult due to rocky soil.
For Brazil this seems like a good thing due to high annual rainfall, although it is not especially beneficial everywhere.
I was suprised to see a shocking lack of depth in this story. When I was growing up, no till drilling was just coming into vogue here in the states. It's primarily used with soybeans, grain crops, and feedcrops (alfalfa). These are close crops that can have a high planting density, unlike corn. There are several benefits to the farmer and the earth, but some negatives as well. From the farmers' point of view, you reduce the number of passes over the same soil, so instead of ploughing, discing, and planting, then cultivating (mechanically removing weeds with another implement dragged with the tractor), you just plant and harvest. So yes, it saves time and fuel.
However, because of the high density and lack of machine access during the growing season, in order to get high yields you have to use herbicides, pesticides and chemical fertilizers. If herbicides aren't used, the existing plant material will choke out the planted crop. If pesticides aren't used insects will destroy the crop because the plant density is so high insects move through it easily. If you don't use fertilizers the high density plants will suck all of the nutrients out of the ground very quickly.
So while there are benefits to drilling, (reduced fuel usage, reduced soil runoff) there are negatives.
To do it right, you do what's called low till. This is based on a two crop strategy. During winter months you grow a winter wheat or winter rye, these strains are planted in the fall and grow extremely quickly in the spring. This crop is harvested and the plant mass is rotated with a chisel plough (a high speed tilling process) into the earth and then the next crop is drilled into the soil. now only pesticide is necessary, because the native plants are turned under and used as fertilizer.
The state of the art has progressed since the 70's.
NO TILL, is the only way to go.
Let's put this way, in Brazil currently there are:
# 26 million HAor 57 million Acres of soybean NO TILL.
# 14 Million HA or 35 Million Acres of Corn NO TILL.
# 1 Million HA or 2,5Million Acres of Cotton NO TILL.
SO...... IS THERE OTHER BETTER ANSWER FOR IT?
ALL FULL DISC DRILL TECHNIQUE.
SORRY FOR MY SPELLING!
HAVE A NICE HARVESTING EVERYONE........