Cover crops: a com­plete soil health over­haul (Part 1 of 3)

Farmer's Weekly (South Africa) - - Contents - Lloyd Phillips re­ports.

A cover crop can play a valu­able role in en­sur­ing that a crop­ping op­er­a­tion grows and re­mains sus­tain­able. Cover crops can be tricky to man­age, how­ever. In this first ar­ti­cle in a se­ries of three, veteran US farmer and cover crop coach Steve Groff ex­plains why a farmer should not give up when try­ing to grow a cover crop for the first time.

The use of cover crops as a con­ser­va­tion agri­cul­ture tool is rel­a­tively new in South Africa. It is there­fore im­por­tant that the coun­try’s farm­ers work to­gether to adapt cover crop­ping meth­ods to suit pro­duc­tion con­di­tions here if this ben­e­fi­cial con­cept is to gain wide­spread trac­tion and achieve the en­vis­aged re­sults, says US farmer and cover crop coach Steve Groff.

“At first, not ev­ery idea will work, but team­work and per­sis­tence will ul­ti­mately pay off,” he says. “Cover crop­ping is a sim­ple and good con­cept, but it’s com­plex to achieve suc­cess with it. Like no-till, cover crop­ping is a tool to achieve healthy soil and re­sul­tant sus­tain­able crop pro­duc­tion. But a farmer must un­der­stand what the tool is in­tended for and how to use it prop­erly for it to be ef­fec­tive.”

Groff ad­vises new­com­ers to start by im­ple­ment­ing cover crop­ping on only 10% of their lands.

“[In this case,] if you fail at first, it’s un­likely to have any sig­nif­i­cant neg­a­tive im­pact on your farm­ing busi­ness. You can then try again along a dif­fer­ent route un­til you get cover crop­ping right. When you get it right, you can grad­u­ally ex­pand its use across your farm.”

Ac­cord­ing to Groff, a crop farmer should man­age the soil to mimic undis­turbed nat­u­ral con­di­tions, where a wide va­ri­ety of plants grow in the soil and help form it. While it may not al­ways be pos­si­ble for crop farm­ers to have di­ver­sity at all times, the goal should be to im­ple­ment it when­ever the op­por­tu­nity presents it­self. This could be in off-crop sea­sons, via in­ter­crop­ping, or on a part of the farm that is be­ing rested.

‘TREAT COVER CROPS AS YOU WOULD CASH CROPS’

Groff stresses that one of the most im­por­tant mes­sages he can share with con­ser­va­tion agri­cul­ture farm­ers is: “If you treat your cover crops the way you treat your cash crops, you’ll set your­self up for suc­cess. Just as you are ready to plant your cash crops at the first op­por­tu­nity that presents it­self, you should be ready when the first op­por­tu­nity to plant a cover crop presents it­self. Soil health can’t be bought, it has to be made.”

He adds that ev­ery con­ser­va­tion agri­cul­ture farmer should have a men­tor – some­one who is al­ready suc­cess­ful at man­ag­ing cover crops. The farmer and men­tor should en­gage reg­u­larly, even if by tele­phone or email, as fre­quent dis­cus­sions stim­u­late the think­ing and anal­y­sis that lead to so­lu­tions and progress.

“Form­ing farmer dis­cus­sion groups is also a great help. Man­ag­ing cover crops suc­cess­fully is far too com­plex to achieve on your own. I’ve been man­ag­ing cover crops for 35 years but I still con­sult my men­tor, Fred­eric Thomas, who lives in France.”

A LONG ROAD TO SUC­CESS

From start­ing with six species of cash crops and one species of cover crop in 1982 on his Cedar Meadow Farm in Penn­syl­va­nia, Groff now grows 14 cash crops and 27 cover crops. As a re­sult of man­ag­ing his con­ser­va­tion agri­cul­ture prac­tices ef­fec­tively, he has im­proved his farm’s av­er­age soil or­ganic mat­ter level from 2% to at least 5,5% over this time.

“My pri­mary goal for the plants grow­ing in my soils is di­ver­sity, di­ver­sity, di­ver­sity,” he says. “My choice of cash crops and cover crops may not be suit­able for South African mar­kets and pro­duc­tion con­di­tions. This is where South African farm­ers must talk to each other and their ad­vis­ers to look at the op­tions. And, as hap­pened with me, South African farm­ers won’t achieve the di­ver­sity that I now have in only a few years. It took me 35 years. Be pa­tient and al­low your­self time to di­ver­sify grad­u­ally and prop­erly.”

Groff is also work­ing to­wards low­er­ing his use of agro­chem­i­cals and in­or­ganic fer­tilis­ers; phas­ing out pro­duc­tion of com­mod­ity crops if this proves fea­si­ble; pro­duc­ing food crops with in­creased nu­tri­tional den­sity; and main­tain­ing his prof­itabil­ity.

His ap­proach on Cedar Meadow Farm en­sures that there are liv­ing roots in the soils year-round. In the 2016 and 2017 sum­mer pro­duc­tion sea­sons, he man­aged to main­tain or in­crease the av­er­age yields of his farm’s var­i­ous cash crops while re­duc­ing over­all in­or­ganic fer­tiliser and agro­chem­i­cal us­age by 39% and 57% re­spec­tively.

“But you can’t just throw on cover crop seed and ex­pect mir­a­cles. Yes, we need to try to mimic the plant di­ver­sity found in na­ture, but even na­ture takes a long time to re­claim and re­ha­bil­i­tate a de­graded soil. If we don’t man­age and treat our soils prop­erly, they won’t be able to har­vest rain­fall. And the nu­tri­ents that we ap­ply to these soils, and the soils them­selves, will sim­ply be washed away by runoff or blown away by wind. This is money go­ing to waste.”

THE PLOUGH IS THE PROB­LEM

Many tillage farm­ers, on see­ing sur­face crust­ing, poor wa­ter in­fil­tra­tion, and wa­ter and wind ero­sion, refuse to ad­mit that their plough is largely re­spon­si­ble. These same farm­ers are quick to point out the pit­falls of no-till and other con­ser­va­tion agri­cul­ture prac­tices.

‘al­low your­self time to di­ver­sify grad­u­ally’

Groff says that he leaves the till­ing of his soils to earth­worms and other ben­e­fi­cial soil life that he has helped to thrive.

“And I don’t have to pay them to do it! They in­cor­po­rate plant residues into the soil and in­crease soil fer­til­ity.”

He adds that tillage farm­ers should be ask­ing them­selves some im­por­tant ques­tions. These in­clude: “Is my soil in bet­ter con­di­tion now than it was 20 years ago?”; “Do I want to im­prove my soil’s con­di­tion over the next 20 years?”; “What is the av­er­age an­nual loss of top­soil on my farm due to wind and soil ero­sion?”; “What price would I be will­ing to sell my soil for?”; and “What is the nu­tri­ent value of my soil?”

He says it is point­less work­ing with a con­sul­tant such as an agron­o­mist un­less this per­son ap­pre­ci­ates and sup­ports what the farmer is aim­ing to achieve by prac­tis­ing con­ser­va­tion agri­cul­ture. A con­sul­tant should be help­ing the farmer im­prove lev­els of soil car­bon and or­ganic mat­ter.

Pho­tos Sup­plied by Steve Groff

LEFT:Steve Groff grows 14 cash crops and 27 cover crops and, as a re­sult, has in­creased his farm’s av­er­age soil or­ganic mat­ter con­tent to 5,5%.

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