|
Vol.3,No.2 |
- The increases in yields achieved by the use of green manure/cover crops (gm/cc's) in system after system are greater than the conventional Concept would have predicted. With increases of only perhaps 100 kg of fixed N and no additional P or K, yields of maize crops have often doubled. (Buckles; Bunch and Lopez; Pretty and Hine, for example) Furthermore, yields of 2.5 t/ha have continued to be produced on relatively poor, humid tropical soils every year for 40 years, with no application of chemical NPK. Of course, what is happening here is due to biological, physical, and chemical dynamics within the soil, not just those of soil nutrients. Nevertheless, according to the Nutrient Quantity Concept, the levels of P, at least, should have become a major limiting factor years ago. Yet applications of chemical P on these soils still, after forty years, give no economic response. (Buckles)
Perhaps it should be added here that "green manure/cover crops" is a technology that is traditional in many tropical areas, but which have only been developed over the last fifteen years in Brazil and Mesoamerica and spread around the world largely by NGO's in the last five years or so. This technology, not to be confused with traditional "green manuring," grows biomass, often leguminous, intercropped with regular crops, under fruit trees, during the dry season, during frosty periods or on degraded soils too poor for cropping (i.e. on land with little or no opportunity cost), thereby adding huge net quantities of high-nutrient biomass in situ to agricultural systems and applying it to the surface where it is highly accessible to subsequent crops. (See Bunch 2001) "Dispersed trees" is another traditional practice around the world which has only recently been studied and promoted in Central America, but which apparently has tremendous potential for increasing biomass production in much of the lowland tropics.
- In Madagascar, hundreds of farmers are now using a System of Rice Intensification (SRI) that frequently achieves yields of 12 to 15 t/ha, and occasionally 18 t/ha, using only moderate amounts of compost and no chemical fertilizer on low CEC, acid soils (a classic case of "low potential soils"). (Uphoff)
Yet the world's rice experts hold that the "biological maximum" for the rice plant is less than 10 t/ha. As one scientist has written, "yields for multiple varieties peak out at about 8 t/ha, even with high N applications, up to 200 kg/ha." (Ladha, et al.). Furthermore, even with applications of 200 kg/ha of N, N assimilation is considered to be the limiting factor for rice production. (Uphoff) In this case, the difference in yields between conventional rice and SRI rice is probably due to a whole series of factors, but whatever the reasons may be, the "low input agriculture is low output agriculture" attitude cannot come even close to explaining rice yields of 15 t/ha on these "low potential" soils with so little N introduced into the system.
- In the case of West Africa's very old, low CEC soils, books based on the Nutrient Quantity Concept claim good yields can only be achieved with major applications of chemical nutrients. (Avery) Yet around people's homes (admittedly on very small plots), African women frequently grow 4-mt-tall, 4 t/ha maize. How? Through the daily application of grey water and kitchen scraps from the household. And the soil is the same soil as in their fields a few mts away.
- The age-old, world-wide regeneration of soils by means of traditional slash-and-burn, or shifting agriculture, techniques cannot be fully explained by the dominant interpretation of the Nutrient Quantity Concept, either. Attempts have been made to somehow help the Concept explain this regeneration of the soil through the idea of nutrient pumping. But the amount of nutrients pumped by trees is frequently not enough to explain the renewed fertility. In many cases, there are precious few nutrients in the subsoil that the trees could pump, even if they were physically capable of pumping the required quantities. And, of course, the concentration of nutrients in the soils from which they are being pumped is only a fraction of what the Nutrient Quantity Theory would consider sufficient for adequate for plant growth.
Furthermore, I have personally asked West African farmers to show me which fields were ready to be "slashed and burned," and close to half of the indicated fields had no visible vegetation on them other than grasses. Certainly farmers whose food supply has depended for generations on their ability to accurately identify regenerated soils could not be mistaken half the time. And if grasses can regenerate soils by themselves, how can the Nutrient Quantity Concept explain this worldwide phenomenon?
- The biomass productivity of natural rainforests is also much higher than its CEC would allow under the traditional Concept. Interestingly enough, in this case, scientists who normally adhere to the Nutrient Quantity Concept freely admit that the rapid recycling of nutrients in tropical rainforests permits tremendous levels of biomass production in the presence of very low levels of nutrients and CEC's in the soil in general. Nevertheless, they have been largely unwilling to entertain the possibility that this same phenomenon of the rapid circulation of nutrients could be the basis of highly productive crop agriculture under similar conditions. Put another way, Nutrient Quantity proponents freely admit in the case of rainforests that "low input forests produce high output forests," yet they refuse to admit that the same principle might be applicable to agriculture in the very same environments. This use of one rationale for proven rainforest productivity while refusing to admit to the possibility of the very same process in agriculture would seem to represent a serious lack of logical consistency.
Nutrient pumping might seem to cloud the above issue somewhat. Nevertheless, many rainforests produce prodigious amounts of biomass above subsoils whose provision of nutrients, even under extremely efficient nutrient pumping, would be less than those nutrients added artificially under many "low external input" systems.
We should also remember that the areas deep in the soil from which these nutrients are presumably "pumped," virtually always possess much lower concentrations of nutrients than do the soils above them. Therefore, even with nutrient pumping, natural forests provide clear evidence that sufficient nutrients for very high levels of biomass production are being extracted from soils with extremely low total concentrations of nutrients. Furthermore, low external input agroforestry systems also pump nutrients. Thus, the logic of the Nutrient Quantity advocates remains problematic at best.
- Chemical fertilizer companies are dedicating millions of dollars to research on "slow-release" forms of chemical fertilizer. This means, in effect, that the fertilizer companies themselves (which, not surprisingly, are among the most vociferous proponents of the Nutrient Quantity Concept) are admitting --through their actions, if not their words-- that the overall quantity of nutrients available at any given time is not the primary issue in productivity.
Of course, one could argue that slow-release fertilizer is being developed because its ecological benefits will demand a sacrifice in productivity from farmers. Nevertheless, research on slow-release fertilizers has shown no such significant reduction in yields. Thus, the very development of this kind of fertilizer is an admission that, at least where this fertilizer is successful in terms of productivity, the constant supply of nutrients is more important than the total quantity available at any particular time.
Given the apparent inaccuracies and even logical inconsistencies of the traditional Nutrient Quantity Concept, it is time to develop a new, more comprehensive and accurate concept of soil fertility in the tropics.
To illustrate the new concept, I will first describe an experiment reported in Ana Primavesi's The Ecological Management of the Soil.(Primavesi)In this experiment, crops were grown in four hydroponic solutions. In the first solution, a normal concentration of nutrients for maximum maize plant development was used, and replenished every 4 days. In the second, twice the normal concentration was used and replenished every 4 days. In the third, the normal solution was diluted 50 times and also replenished every 4 days. And in the fourth case, the solution used was diluted 50 times the normal concentration, as in the third case, but was replenished every 2 days.
Plant growth (measured in grams of dry weight) in the second case was less than in the first. In the third case, as either theory would predict, the growth of the plants was 28% less than in the first. But in the fourth, quite surprisingly, the growth of the plants was slightly superior to that in the first case. That is, even when the nutrient solution was 1/50 what the traditional Nutrient Quantity Concept would have seen as optimal, the plants grew equally well, as long as the solution was replaced frequently enough and the roots could access the nutrients.
That is, crop growth above a certain extremely low concentration, does not depend on the concentration of nutrients. It depends, rather, on the constant access of plant roots to the nutrients, even when these nutrients exist in very low concentrations. The Nutrient Quantity Concept's remedy of increasing the concentration of nutrients by applying large amounts of chemical fertilizer misses the point almost entirely. What is needed is a constant supply of even a very small but well-balanced amount of nutrients over time, and the unobstructed access of plant roots to these nutrients.
This experiment shows that the relationship between concentrations or overall quantities of nutrients and plant growth is, above a certain minimum concentration, altogether nonexistent. As long as plants enjoy the right conditions of nutrient balance, accessibility to nutrients, and a constant resupply of nutrients, the relationship between the concentration of nutrients in the soil and its productivity is either zero (i.e. there is no relationship) or negative (i.e. more concentrated nutrients reduce plant productivity).
So why is this fact more relevant to tropical soils and farmers than to temperate-zone soils and farmers? Very simply, tropical soils tend to have fewer cation-exchange sites, and therefore lower concentrations of nutrients. Because of this paucity of CEC, it is also much more difficult and costly for farmers to raise those concentrations of nutrients over the medium to long term. Second, the ambient heat of the tropics makes it difficult or impossible for plants to create the osmotic pressure to be able to absorb nutrients from highly concentrated solutions. (Primavesi) Therefore, plants in the lowland tropics often thrive better on more limited concentrations of nutrients (as was illustrated by the second case in the experiment above), as long as the remaining conditions are fulfilled.
Thirdly, farmers who work by hand or animal traction, can more easily micromanage their soils, creating varied microenvironments, in some of which nutrients are accessible, even if the total soil environment is deficient in accessible nutrients. And lastly, while northern farmers can often afford to fertilize their soils more heavily than need be for present purposes, resource-poor farmers in the developing countries just cannot afford to over-fertilize. Furthermore, in high-rainfall or steeply sloped areas, resource-poor farmers would lose more of those nutrients than do their northern colleagues.
The new concept of soil fertility emphasizes not the concentration of nutrients in the soil, but rather the maximization of the access of plant roots to soil nutrients. Thus I will herein call it the Nutrient Access Concept of soil fertility. The Nutrient Access Concept of soil fertility in the tropics posits the following:
Maximum plant growth can best and most cheaply be achieved in the tropics by:
Pre-workshop meeting - Three or four extension service providers meet with three or four farmers groups' representatives. In this forum the match making model is explained in detail by NECOFA team so that the group is integrated into the arrangement/organization of the affair. Each service provider and farmers' group representative gives a brief of their groups'/organisations' vision, objectives and the activities they are involved in.
A "match making" workshop is planned. The group agrees on the date, venue and the other service providers'/farmers groups' representatives too be invited. A workshop organizing committee is appointed comprising of at least one service provider, one farmers groups' representatives and the Necofa team. The organizing committee is charged with the responsibility of addressing all logistical issues related to hosting the workshop.
"Match making" workshop - in this workshop representatives of service providing organizations and representatives of community groups from the target area are invited. Necofa (being the host and umbrella organization) takes the opportunity to elaborate on its vision, mission, objectives and activities. This opportunity is used to recruit the participants into Necofa (as organizations/groups or as individuals). The other organizations and groups are given opportunity to expound on their objectives and activities. The different groups are then asked to answer the following questions:
During plenary session matching of groups/organizations is done based on their response to the above questions. A "match making" show is then planned. The date and venue are agreed on in the workshop. The organizing committee is expanded to have at least five members (drawn from both service providers and community group with Necofa taking the leading role).
"Match making" mini-show. In this mini-show the service providers exhibit:
This is an open day where everybody in the vicinity is encouraged to attend. All possible avenues of publicity are involved (including the mass media); a programme is developed to include short speeches and some entertainment is planned (especially traditional dances, poems or choir by school children e.t.c).
Priority none -agricultural messages are also exhibited, presented or addressed during the show e.g. HIV/AIDS awareness campaign, security etc. In this show friendships, collaborations and partnerships in endeavors are planned and organized.
Necofa -Kenya with financial assistance from gtz-KASIM organized its first such forum in Nyanza province on:
Step (i)_________ 3rd April, 2001
Step(ii)_________4th April, 2001
Step (iii)________26th April,2001
The theme was: "Ecofarming partnerships for community Development."
Other such forums have been planned to be held in other regions of the country. Lessons learnt in these forums will be used to improve in the organization of the subsequent ones.
held in Yaounde on June 9th, 2001 at Bobine d'Or, Ekono
The NATIONAL QUARTERLY MEETING of the NECOFA Cameroon Chapter ( NECOFA - CC ) was very colourful successful in its Agenda and in its representation. Many members participated which at the same time represented or had Institutional or Organisational mandate.
Following Institutions/Organisations were present at the meeting:
The Non Governmental Organizations represented were:
During the NATIONAL QUARTERLY MEETING the different NECOFA - CC branches were represented by Mr. Richard ANAGHO, Mrs. Florence Folefa, Mr. Kum Sylvester,Mr. NGAINDO Boniface.
The activities were highlighted as follows:
South West ( presented by Florence Folefa ). In the last three months, the South West branch was involved in three main activities.
A report from Mr. Kum - NECOFA Kameroun Coordinator
A two week's course on MONITORING AND EVALUATION IN DEVELOPMENT PROJECTS took place from the 15th of May 2001 in Feldafing - Germany. The Course was organised by the German Foundation for International Development (DSE). The course involved 27 participants from Bangladesh, Brazilia, Cambodia, Cameroon, China, Ethiopia, Germany, Japan, Kenya, Nepal, Nigeria, Uganda and Vietnam. During this programme, participants shared and gained experiences on the concept of monitoring and evaluation in development projects.
After this course, upon the invitation of the International Coordinator for the NETWORK FOR ECOFARMING IN AFRICA (NECOFA), Mr. Sahle Tesfai, I travelled from Feldafing to Kassel. While in Kassel, together with the International Coordinator of NECOFA, contact meetings from the 30th to the 1st of June 2001 were held with some University students, Deans of the University of Kassel and Gottingen and some institutions.
The first of such meeting was held with some international student participants in a University staff development course in the University of Kassel. They came from mostly Uganda, Tazania and Egypt.
During this meetings, they were introduced to NECOFA, its objectives and activities . They were very much impressed to have learnt about the existence of such a Network and promised to have Ecofarming included in the Curriculum in the Faculties of Agriculture in their various countries. They further promised to have themselves registered as members of NECOFA immediately they go back home, and even start sensitization and establish NECOFA in countries where the Network is not yet existing, as was the case of Egypt.
A similar meeting was held with some German students carrying out a course on Project Management in the University of Kassel. They were also introduced to NECOFA and its objectives. After this presentation, they were very curious to know exactly the type of Ecofarming activities going on in Cameroon. In this light, they were highlighted on HELVETAS sponsored NRM projects, which are ecological and socially sound. They were also very much interested to know the possibility of students from the University of Kassel to carry out their internship with NECOFA Cameroon. It was made clear to them that NECOFA Cameroon is quite prepared to welcome students to carry out internship in any ecofarming component of their choice.
We also held meetings with the Deans of the Universities of Gottingen and Kassel. In this meeting, we discussed possibilities of NECOFA collaborate with them. In simple terms, they said collaboration will be by sending German students to Cameroon for intership and NECOFA members can also benefit from a certain number of scholarships every year to gain professional experinces in their Universities. They said scholarship forms shall be made available through the International Coordinator of NECOFA. Furthermore, they encouraged many applicants to apply for these scholarships. This to them, would be used for requesting of more funds for the scholarships.
Another important contact was that of the applied cultural research in Gottingen. Here, we had lengthy discussions with Dr. Rolland Drubig and Dr. Holger Martens both of the Institute for applied cultural research. During our meeting, they said their institute has as of their objectives to solicit funds for development projects for organizations in developing countries. They said that project proposals should be channeled through the International Coordinator of NECOFA to transmit to them. They study these projects and transmit them to the appropriate donors for fundings.
We further had meetings with the Herman Heldberg and Norbert Muller- Kluge, all of "Naturkost und Naturwaren". They import and supply ecologically produced products like pineapple, orange, bananas, lime etc. to super markets in Germany. During our meeting, they were very interested to know the possibilities of NECOFA to export to them Eco- products for super markets in Germany. I made it very clear to them that NECOFA is very ready for this business and would appreciate an immediate start.
A similar contact was also made with Mr. Steffen Andreae of Ethio Trade Agency. They also import and supply Eco- products to super markets in Germany. Mr. Steffen Andreae said after knowing how many super markets will be in need fo what sort of products from Cameroon, he shall then visit Cameroon and see for himself how these products are being produced.
There were many places to be contacted but due to time contraint (just 3 days), it was not possible for us to contact all the envisaged places.
"Ecofarming" is the only method for improving crop and livestock production.
Mrs. Jolly Kabirizi
Greetings from Uganda. How are you?
We have started a number of projects aimed at improving livestock production through use of ecofarming technologies such as use of Calliandra fodder trees instead of using concentrates; use of forage legumes to improve animal productivity and soil fertility. My PhD project titled "Methods for improving dissemination and adoption of fodder bank technologies on smallholder dairy farms in Uganda" was approved for funding by DANIDA. I am very happy about it. I am even happier to see that many farmers in Uganda are now realising that "Ecofarming" is the only method for improving crop and livestock production. Farmers have been depending a lot on inorganic fertilisers to improve productivity of fodder.
We are eagerly awaiting for the outcome of next year's conference in Uganda.
We are keeping our fingers crossed so that the venue remains the same and at the same time funds for the workshop becomes available.
Greetings to all.
Jolly Kabirizi (Mrs)
Namulonge Research Institute
P.O. Box 7084 Kampala, Uganda
Dear Jolly Kabirizi ,
We all submit our congratulations to NECOFA-UGANDA for its activities and special congratulation for the approval of your PhD project.
Good News from ZAMBIA
It appears things are looking better. Membership is gone to 40. Our registration is receiving final consideration at the Registrar of Societies / Associations. Membership forms ( the rest ) will be dispatched soon.
Our project proposal to officially launch NECOFA is being considered at the Germany Embassy - Lusaka.
My Sunnhemp booklet is ready for publishing.
Please note my change of E-mail address to read chandud@zamtel.zm
Greetings
Gabriel Kaunda
Enterim Coordinator.
NECOFA - Kenya proposes the development of "NECOFA ANTHEM"
Mr Samuel K. Muhunyu and writes, certainly waiting for an immediate feedback.
I propose that NECOFA develops an anthem. Please find out if the NECOFA BRANCHES in other countries support the idea.
If they do, I have attached a copy of my proposed anthem, which can be used as a basis for evolving/developing one.
In the following, my suggestion/proposal:
PROPOSED NECOFA ANTHEM
Beneath the cloudy, star spangled sky-the sun provides life to mother earth
Nourishment for flora and fauna is primordia in soil, air and water.
Ecofarming is the balm for the exhausted, scorched earth;
A fountain for sustainability of both man and woman.
NECOFA is the avenue to Ecofarming
"Mama Africa" needs NECOFA for poverty eradication and development.
Together we have the noble task and responsibility of building Mother Africa - through NECOFA
GOD BLESS NECOFA