oh to be the Conservation Agriculture (CA) Coordinator

From a recent email ... have been to busy or tired to type lately.

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Hi [           ] –

This is a lot of data, so let me summarize a bit.

The Mechanics

Conservation Agriculture is based on three pillars:

1)      Retention of crop residues (maize stalks, chopped weeds, etc. are left on the field to rot, be eaten by termites, etc.) … so, *no burning or grazing* during the dry season.

2)      Minimum tillage – only the places where crops are to be planted are dug, i.e., small basins that are dug in rows at a predetermined spacing. The rest of the soil surface is only tilled superficially to chop weeds. *No ploughing or digging of the entire surface*

3)      Crop rotation with legumes … at least 33% of the crops planted on a farmer’s cultivated should be legumes … *no monocropping of maize*

Why?

1.       Leaving the dry matter on the soil serves a number of purposes:

a.       Dry season:

                                                               i.      Shields topsoil from sun, lower relative soil temps (making a more condusive environment for beneficial soil bacteria and other micro/mesofauna)

                                                             ii.      Termites consume dry matter slowly. This creates micropores in the soils (allowing for improved water infiltration and retention), plus the termites bring up soils from depth that contain vital soil nutrients.

b.      Wet season:

                                                               i.      Residues prevent water erosion during acute rainfall events;

                                                             ii.      Prevents excessive soil moisture evaporation, mitigating dry spells,

                                                            iii.      Hinders the growth of competitive weeds.

                                                           iv.      Slows percolation of water into the soil, mitigating against nutrient loss during acute rainfall events.

2.       Min. tillage … Essentially, inversion of the topsoil (ie. Ploughing) results in oxidation of soil organic matter. This wrecks the soil’s ability to hold nutrients, moisture, etc., etc. Soils under conventional tillage eventually become “massive” in structure, not size-wise, but meaning they become enormously hard when dry. Not tilling allows SOM to build up, more ability to hold nutrients, etc.

3.       Crop rotation with legumes … not a hard one; provides biological fixation of atmospheric nitrogen (i.e., nitrogen-fixing) that benefit subsequent grain crops, plus valuable sources of household protein. Monocropping with hybrid maize essentially zaps even the best soil of all its inherent fertility in about three to four years.  

Other Mechanics:

1.       Timely application of fertilizers and seeds:                                           Apply inputs at the right time; have fields prepared so crops can utilize the first rains.

2.       Continuous weeding (or many instances of weeding):                    Weeds compete for water and nutrients; also, we want to cut back on the weed seed load in a farmer’s field to eventually reduce

weeding labour.

How we’re doing it:

The project was modeled after a project in Zimbabwe about five years ago, along with existing CA projects under the Conservation Farming Unit (CFU) of Zambia Natl. Farmers’ Union (ZNFU).

We have 1,400 beneficiary farmers in 3 districts (Kaoma, Mongu, Senanga). These beneficiary farmers are led by 170-odd lead farmers (8-10 ben. Farmers per lead farmer), organized under various Area Farmers’s Associations (AFA) in the three districts (4 AFAs in Kaoma, 3 in Mongu, and 6 in Senanga). Each AFA’s CA activities are lead by a single Field Extension Worker (FEW), so we have 13 of those, who receive a monthly salary of K300,000 and are largely responsible for the monitoring of all the CA farmers in their AFA.

Beneficiaries receive 25kg of fertilizer (half/half D compound and Urea), seeds for maize / groundnuts / cowpeas (and/or) sunflower (Kaoma gets sunflower). Lead farmers get double fertilizer and maize seed, with the intention of them making a “control plot” where they are supposed to plant maize conventionally to contrast the difference between CA and conventional ag. Currently, we recommend to beneficiary farmers that they have 50% maize, 25% cowpeas, and 25% groundnuts on a 40x40m “practice” plot.

By end of May 2012, we intend to increase the number of beneficiaries to 3,000.

I won’t go into the challenges and innovations, because that would make the email into a e-book. We’ll discuss those offline.

One document to note is the short discussion paper (uncirculated) that I drafted regarding the ripper; though this isn’t official, we aren’t seeing much use of that particular implement for the reasons mentioned within.

Let me know if you have any questions,

Carl

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Carl T. Wahl - Conservation Agriculture (CA) Coordinator

Concern Worldwide, Zambia

Plot 41A, Lyambai Rd., Mongu, Zambia

011-260-979-045004

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