Tuesday, October 4, 2011
At Manda Wilderness Agricultural Project the major problem was and is still poor soil fertility. The farm where the project is being undertaken lies less than 200m away from the shores of the great lake Malawi. The soils are as one might predict highly draining poor beach sandy soils.
Several volunteers and managers had worked at the project and managfed to improved on other aspects of production but not soil fertility. I then listed it as one of my major goals to improve the fertility of the soil so that a variety of vegetables can be grown other than just s herbs an a few salads that the farm was specialising on. My first action ws to get the soil tested , so I sampled two batches of soil. One of our guests volunteered to take one sample with him to Kenya where soil testing laboratories are more efficient than in Mozambique while we took the other sample to the Mozambician national soil analysis lab in Maputo.
While I was waiting for the results to give me directions I started constructing a worm farm. The place is of very limited resources and I only managed to get one large plastic container, a guaze wire to cover on top. I partitioned the innerside of the container into two, the bottom part for reception and storage of worm wee and the top part where my worms will stay. There wasn't even anything to use as a lead that can fit on that large bin of about 60cm diameter so I took a piece of guaze wire that I had left on my chicken tractor construction and put it on top as a cover with stones tied around to stop it from being blown away by wind. The result of this interesting craftwork is that shown in the photo above.
I then started collecting worms from the compost piles and from anywhere around the farm as there was nowhere to buy the breeding stock. After about three weeks of collecting, domesticating and feeding of only a handfull of worms we started to harvest the 'precious liquid' vermileachate. The liquid become more and more stronger at every harvest till it was dark black in colour a sign that the worms were multiplying very rapidly and were happy with the environment. One day when we decided to harvest the worm cast we were shocked to find out that we had over two kgs of worms in stock. We took some to the compost piles to help with decomposition and some we directily place them under mulch in vegetable beds.
A month later the Kenyan Laboratories brought the results indicating that apart from lack of nitrogen the soil was too alkaline dew to the use of Lake Malawi water for irrigation and one of the few available options to control that situation organically was to add "organic acids" and Vermileachate was listed as one of the best sources.
The Mozambician labs eventually sent their portuguees written results two months before my term was over. Thank god the nutrient status were quoted in scientific chemical symbols so though I couldn't read their analysis reportr myself I could see that our soils had very low levels of potassium and nitrogen. Even the compost samples that I had sent together with the soil had insufficient Nitrigen to cover up the difficiency, the four litres of worm wee that we were geting couldn't cover up the defficience on the whole farm either. So a plan come to my mind - to visit the famous bat full baobab tree and find out how much Guano (bat manure) was loaded inside its cave. The task was a marmoth one. The cave had not been entered since the liberation war in Mozambique and none of our bush guides was willing to lower himself inside the 4m deep,dark and scary 2000 year old cave, so I took the responsibility to myself.
We managed to harvest about 60 kgs of guano and I knew I had found one of the best natural sources of nitrogen and potassium. I conservatively used it in compost making and make some of it into guano tea by soaking in water it for 24hrs. I also blended it with the vermileachate and produced a thic black tea that I was diluting 1 part : 10 . God knows what blend was that but what I can testify is - it brought the first carrots ever on the farm to the kitchen.Carrot production was totally impossible at this farm dew to high infestation of nematodes so I believe dew to the nematocide properties of the guano tea blended with the vermileachate, naturaly and simply cures the problem.Ofcourse the chicken tractor effect also contributed, but whatever the reason was ,it was a function of ecological thinking and designing that I am proud of.
Posted by Tarirai at 3:32 PM