No till - No yield
- I have selected broad beans (vicia fabia) to compare Natural Farming with Traditional Farming in the Alentejo region in the South of Portugal. Broad beans are a cool season annual plant that is traditionally grown by local farmers and by farmers in most other Mediterranean regions. Broad beans are also ideally suited to Natural Farming because they are robust and can grow without fertilizers in an unplowed field and normally compete well with weeds and grasses.
I have compared the growth and estimated yield obtained by Natural Farming without plowing in my own gardens and fields with the growth and estimated yield obtained by Traditional Farming in the plowed fields of my neighbors.
The beans are sown in autumn and harvested in April. I inserted each bean in an individual hole in the unplowed soil. I never fertilize my soil. My neighbors sow by drilling the beans in the plowed soil. My neighbor’s soil has been fertilized for previous crops.
The soil is heavy clay. The climate is semi-arid: 500-600 mm from October to April; no rain and high temperatures for the rest of the year.
I have noted the (plant height in cm – the expected yield) in brackets after each test plot.
1. Traditional Farming (plowing, no irrigation, manure for previous crops)
(120-140 cm – good yield)
2. Natural Farming (no fertilizer, no plowing for 12 years)
2a) Field 1 (average soil)
(25 cm – no yield)
2b) Field 2 (average soil after 3 years of mulching, irrigation)
(0 cm – no yield)
* The grass and weeds in this field crowded out the broad beans at an early stage.
2c) Field 3 (best soil)
(35 cm – no yield)
2d) Garden 1 (very good soil after 10 years of soil improvement)
(140 cm – good yield)
2e) Garden 2 (good soil after 6 years of soil improvement)
(120 cm – good yield)
2f) Uncultivated soil (quasi virgin soil between fields, irrigation)
(70 cm – low yield)
The results show that Traditional Farming in arid regions obtains good results by plowing and manure (1). Without plowing only very little growth and no yield is obtained (2a and 2c). When mulch from other fields is added for 3 years and when irrigation is used (2b) improved growth of grasses and weeds is obtained which crowded out the beans; again no yield. When garden soil is improved by incorporating compost and by mulching for 6 and 10 years, respectively, good growth and good yields are obtained (2d and 2e). The improved garden soils also produced better results than the quasi virgin soil between fields which has probably not been cultivated for centuries (2f).
This clearly demonstrates that plowing is a simple and easy means for growing food crops in arid regions. To obtain the same results without plowing soil needs to be improved by concentrating organic matter from many fields in one small area for use as compost and mulch for a number of years. This is suitable for gardening but not for farming. The size of the garden is further limited by the water available for irrigation. In the summer I can irrigate ¼ acre, which is less than 1% of the total area. Again this is not feasible in farming. With plowing a farmer can use 100% of his land even without irrigation.
The myth that nature will create a garden all by itself is also not correct. The quasi virgin soil between the fields (2f) with soil that has probably not been disturbed for centuries produces only half of what the improved garden soil or the plowed fields produce.
Nor is it correct to assume that soil will improve of its own simply by stopping to plow. After 12 years without plowing the soil is still as poor as ever.
Portugal, April 4, 2009
PS: I have taken pictures of each test plot. I have yet to visit my neighbors to take pictures of their fields. If there is an interest, I can try and post them somewhere on the Web.
- --- In email@example.com, "diebrand" <diebrand@...> wrote:
>Hi Dieteri'm sure you might have tried growing Quinoa. i've read, it can handle heavy clay and even draught.
> We have cork oaks on most of our land. Cork oaks can grow on very dry clay soil without a drop of water during the summer. No other food crop can survive under these conditions. Therefore it is usually not possible to grow food crops under cork oaks. Pastures with cork oaks can be used for grazing goats, sheep and pigs during at least part of the year.
> Dieter Brand
> --- In firstname.lastname@example.org, "gunther1753" <gunther.jerabek@> wrote:
> > --- In email@example.com, Dieter Brand <diebrand@> wrote:
> > >Hi Dieter
> > i remember a doku-film about cork-oak plantations in portugal. apparently this is a beautiful eco system for wildlife and plants. i wonder if NF could be practised in between those trees as in a forest garden. maybe reforestation would be the best option in dry areas as yours. have you any info on that?
> > regards guenther