Wednesday, August 12, 2009

YAM CULTIVATION WITHOUT TRADITIONAL MULCHING





YAM CULTIVATION WITHOUT TRADITIONAL MULCHING ALLEVIATES POVERTY.
Teaching farmers the importance of roots to the yam plant!
15 May 2009


Vincent Gudmia Mfonfu

MSc Agriculture/Forestry Extension
Agricultural/ Environmental Journalist
Last Great Ape Organisation (LAGA)
Tel: (237) 77 86 26 93


Dr Daniel Ngongho Mfonfu, (MD)Independent Researcher
Tel: (237) 77 60 12 07,
danielngongho@yahoo.com
Website: http://www.mfonfudaniel.blogspot.com/
C/o St Mary Soledad Catholic Health Centre, P.O. 157, Mankon, Bamenda - Cameroon

Emmanuel Gabila Mfonfu
Environment Inspector; MSc Agric Education/Environmental Science
Divisional Delegate of Environment, at Ndop.
Tel: (237) 77 83 98 94



Abstract

In the North West Region of Cameroon, a hard-working population cultivates yams during the period from November to March and destroys the same crops in June and July through traditional mulching practices.

Traditional mulching, as practised in the North West Region, is a weeding process whereby the farmer uses a hoe to remove weeds from the ridges and the furrows of the yam garden, and add soil collected from the furrows and ridges on the yam tubers to prevent exposure to sunlight and cold. The result of the traditional mulching is the destruction of the roots of the yam thus leading to early withering of the foliage, production of premature yam tubers and thus a poor yield.
In our yam garden we do not practise traditional mulching; our yield is good; thus we have decided to write and publish our yam cultivation experience for the benefit of humanity with the goal of promoting yam cultivation with hand weeding, and stopping traditional mulching in the North West Region.

Our yam cultivation without traditional mulching consists essentially of composting, making of ridges, application of organic manure, staking before planting of yam sets, hand weeding, and mulching of sweet yams with soil from outside the yam garden.

The biggest Nkambe yellow yam tubers harvested in November 2008 weighed 11kg and the sweet yam tubers 2kg.

Staking of yams is imperative for the healthy growth of the yam stems and foliage. The sites of the planted yam sets are soaked with water to stimulate germination since planting is done during the dry season.

Mulching of sweet yams is done by carrying soil from elsewhere out of the yam garden and putting it on sweet yam tubers as they grow upwards.

We advise that yam cultivation should be a family enterprise involving husband, wife and children; with husband helping to stake the yams. Men should also plant yams because yam cultivation will provide employment and income to them as well.

The change of attitudes and habits of farmers can only be accomplished by working with families in their communities through training and creating demonstration farms.

The excellent yield produced by using compost manure would discourage farmers from burning ‘ankara’- a ridge of organic waste that is burnt by a farmer to produce in the short-term good yield from planted crops, but the burning destroys the soil for years.

The hoe should be the companion of the farmer during the tiling of the soil and making of ridges while the hands remain the natural companion of the farmer during weeding. The machete is used to remove tough weeds. Our yam cultivation method with hand weeding with all its components is the key to solving the problem of unemployment, poverty and food insufficiency, deforestation and environmental degradation.

We recommend that our method of yam cultivation with hand weeding should be applied to the cultivation of other tubers such as cassava and cocoyam. We pray the local and national authorities to embrace and promote our yam cultivation techniques – yam cultivation with hand weeding only.

This is our modest contribution to the wellbeing of humanity inspired by The Almighty God!

INTRODUCTIONIn the North West Region of Cameroon, an industrious population cultivates yams during the period from November to March and destroys the same crops in June and July through traditional mulching practices.

In September 2007 as we passed through a village we observed that the foliage of their yam plants had withered whereas ours was still very green (Picture1). In September 2008 as we passed through the same village we saw no yam gardens; the farmers declared to us that the yield of the previous year was very poor thus they did not cultivate yams again. The consequences of not cultivating yams by these farmers are very serious: there will be no yams for the population to eat and to sell, thus aggravating poverty and poor health from inadequate nutrition. The only prominent difference in the cultivation process was the practice of traditional mulching by the farmers.

Mulching is a soil conservation practice. By definition, mulch is any material laid on the soil surface, to decrease erosion, conserve water and reduce weed growth (Picture2). It can be a mixture of straw, rotting leaves or compost that is placed around a plant to protect the roots and keep the soil moist. Mulching is a vital component in agriculture; it serves to modify crops' environment so as to increase yield and quality (Valerie SOPHIE Agrinews-online).

Traditional mulching, as practised in the North West Region, is a weeding process whereby the farmer uses a hoe to remove weeds from the ridges and the furrows of the yam garden, and to add soil collected from furrows and ridges on the yam tubers to prevent exposure to sunlight and cold. The result of the traditional mulching with the sharp hoe is the cutting and destruction of the roots of the yam (Picture3) thus leading to early withering of foliage, production of premature yam tubers and thus a meagre yield. Traditional mulching is usually practised in June and July.

Poverty alleviation (or poverty reduction) in this context is any process which seeks to reduce the level of poverty in a community; increase the revenue or income of individuals or families in a community.

The UN millennium development goal envisages eradicating extreme poverty and hunger through reducing by half the proportion of people who suffer from hunger, while the World Health Organisation states that ‘Primary health care includes - promotion of food supply and proper nutrition’- (Declaration of Alma-Ata International Conference on Primary Health Care, Alma-Ata, USSR, 6-12 September 1978)

Yam cultivation without traditional mulching would improve yam yield, ameliorate the availability of food, ensure the sustainability of good nutrition and alleviates poverty and hunger.

In our yam garden we do not practise traditional mulching; our yield is high; thus we have decided to write and publish our yam cultivation experience for the benefit of humanity.

GOAL
Improve yam yield and alleviate poverty amongst yam farmers in the North West Region of Cameroon in particular and in Cameroon in general.

OBJECTIVES
- Describe our improved yam cultivation practice
- Describe the basic functions of the parts of the yam plant
- State the advantages of yam cultivation without traditional mulching.
- Promote our yam cultivation method with all its components.

METHOD
We describe our experience in yam cultivation, with particular reference to yam cultivation in 2008, under the following components: preparation of compost, tilling of the soil and making of ridges, acquisition of yam sets, yam staking, planting of yam sets, weeding, mulching, fighting of pests, application of manure, and harvesting. Pictures of yam gardens taken in the course of the year are used as illustrations.

Compost
From January and through out the year organic household refuse is deposited in a pit of 180cm long x 130cm wide x 130cm deep (Picture4). All members of the compound are educated to sort and separate the organic waste (biodegradable waste, waste that can decay) from household refuse and dump it in the compost pit. The organic manure is extracted from the pit in January and put in the ridges (Picture5).

Acquisition of yam sets
Yam sets are obtained from the previous harvest, but if they are inadequate, more yam sets are purchased from the market. The types of yams planted according to local appellation are Nkambe yellow yams and sweet yams. The yam sets weigh between 300 and 700grams (Picture6).

Tilling of soil
Ridges are made. The ridges are deepened by 20cm below the ground level. The ridges are 2m apart from the middle of the ridges. The deepened ridges are first of all filled with organic waste that is not yet decayed such as previous dry yam foliage and other recent organic household waste, and covered with soil. Then the decayed organic compost from the pit is well mixed with the top soil during the constitution of the ridges (Picture7). The ridges are raised high, about 50cm from the ground level. Hoes are used to till the soil and make ridges.

StakingIndian bamboos are used for the staking of the yams. The bamboos are planted at about 40cm to 50cm apart on top of the ridges, two successive bamboos are made to cross each other at the top; they could be reinforced at the crossing point with a third bamboo in the middle (Picture8). The bamboos should be of moderate height about 2 to 3 metres above the soil. Staking is done before the planting of the yam sets.

Planting
The yam sets are planted on top of the ridges, one per bamboo, at the inner aspects of the two bamboos with the budding end of the yam set towards the bamboo (Picture9). The yellow yam sets are placed at about 5 cm into the soil and the sweet yam sets at about 15cm because the sweet yam tubers grow upwards. Generally the yam sets of sweet yams are placed on the empty (without grass) floors of the furrows and the ridges made on them ensuring that grass or manure is not put on the yam sets in order to prevent suffocating the yam set during shooting. The site where the yam set is planted is soaked with a litre of water as the planting is done during the dry season. Each category of yam is planted at the same stakes. Corn and non-climbing beans are planted by the sides of the ridges. When yam sets begin to sprout the stems are directed to climb on the corresponding bamboos. When several stems sprout from one yam set the two healthiest stems are selected and the rest cut off. The growing stems are monitored frequently, every two weeks, to ensure that they climb on the bamboos correctly

Weeding
The yam garden is weeded with the hands only (Picture10). The machete is used to remove strong and tough weeds. Weeding is done every two months. The weeds thus removed are put in the compost pit.

Mulching of sweet yams
Mulching is done by carrying soil from somewhere else out of the yam garden and putting it under the sweet yam stem in June (Picture11); this is repeated whenever the rising sweet yam tubers crack the surface soil as they grow upwards until maturity.

Application of other organic manure
In addition to the organic compost manure, chicken droppings are applied on the ridges at the beginning of rainy season (in April) to enhance good foliage growth and in June to improve the development of the yam tubers. The chicken droppings are obtained from our small scale poultry (Picture12).

Fighting pests
The most common pests observed are small yellow ants that feed just at the spot where the tubers are being formed sucking away most of the glucose from the leaves, this occurs from June at the beginning of tuber formation. The main stems in the soil are monitored regularly as from June and ants identified killed with appropriate pesticides.

Harvesting
Harvesting of yams is done when the leaves of the yam are withered and dry usually as from mid October (Picture13and Picture14). The sweet yams are harvested and cooked immediately because they are easily damaged by cold.

RESULTS
The harvest of 2008 was good as usual. The biggest 46 of the 88 Nkambe yellow yam tubers harvested and 12 of the 24 sweet yam tubers were weighed (Picture15); the highest weight was 11kg for the Nkambe yellow yam and 2kg for the sweet yam (Table1and Table2).

DISCUSSION
Composting is the purposeful biodegradation of organic matter, such as yard and food waste.
Composting up cycles organic kitchen and yard waste into an extremely useful humus-like, soil end product, permitting the return of vital organic matter, nutrients, and particularly bacteria, that are vital to plant nutrition to the soil. Composting will increase agricultural productivity and maintain a clean and healthy environment.

The major advantages of composting:
- Good organic manure is obtained for the improvement of the fertility of gardens and farms
- Very little house hold refuse is produced from the compound
- The city refuse van collects very little household waste from compound, only non biodegradable wastes (plastics; metals; broken plates, glasses and bottles) will be carried away.
- Reduces environmental pollution by decreasing the quantity of refuse at the urban refuse dumping site and in the production of carbon dioxide through burning of the refuse during the dry season (Picture16).
- Organic manure can be sold by compounds to gardeners and farmers providing good business and reducing unemployment at the level of each family.
- Organic manure is cheaper to produce than buying the expensive chemical fertilisers.
- Prevent the pilling of household refuse in the streets that rot for months creating a very serious health hazard.
- Enriching the soil with compost manure will prevent farmers from cutting down virgin forest to cultivate yams and other crops because previous farms are no longer fertile and discourage them from carrying out the traditional yam cultivation based on slash and burn practices.
- Shifting cultivation will be reduced, habitat of animals will be conserved, and deforestation will be greatly reduced thus the habitat of endangered animal species will be preserved.
- The excellent yield produced by using compost manure will discourage farmers from burning ‘ankara’- a ridge of organic waste that is burnt by a farmer hoping to produce in the short-term good yield from planted crops, but that destroys the soil so bunt for years.
- At the level of municipalities units could be created to produce organic compost manure at the municipal refuse dumping site in order to solve the problem of unemployment and poverty.
Although we use the compost pit, other methods of composting could be exploited provided the refuse is protected from spilling over in the compound or the compost becoming a feeding ground for domestic animals and rats. Composting should be carried in both urban and rural communities.

The food markets produce tons of organic waste suitable for composting; when farmers would have had a positive experience with the compost manure they would go back home with organic waste after selling their produce at the markets. Vendors at the markets would be educated to sort their waste into organic and non organic; the organic waste could be offered to farmers or persons desiring to compost at a token motivation.

Making of ridges
The advantages of making ridges are
- The furrows are straight
- Staking is easier
- There is large and effective surface area with superficial manure for the roots of the crop
- Erosion is easily and better controlled (Picture 17)
- Manure is retained in the farm
- Water is retained in the garden
- Weeding is easier because of reduced surface area
- Rain does not beat ridges flat

In a large scale farming the ridges can be raised higher only; raising the ridges only also facilitates harvesting; there will be little digging.

Acquisition of yam sets
Initially yam sets are purchased but is important to always reserve yam sets from previous harvest because they are usually very expensive during the planting season.

Staking with bamboos
Staking of yams is imperative for the healthy growth of the yam stems. Staking should be done before the yams are planted because when the yam stems sprout the heads grow upwards looking for a stake to climb and if nothing is found they fall on the ground and would not be able to climb a stake effectively again. We use Indian bamboos for the staking of yams; other methods of staking could be practised but the most important aspect of staking is that the height should be about 2 to 3 meters above the ground. Yam staking is the most difficult component of yam cultivation for the woman since yam cultivation seems reserved for the woman in the North West Region; men participation in yam cultivation is highly recommended (Picture18). When staking is not done before planting the stems get entangled on the ground and are difficult to separate (Picture19); during weeding the stems are destroyed thus poor yield; the spines of the entangled stems could wound the farmer.

Planting
Each category of yam should be planted at same stakes because some species of yams produce heavy foliage for example sweet yam produces larger leaves and more voluminous foliage than yellow yams, consequently if they are planted together the sweet yam leaves will overshadow those of the yellow yam thus leading to poor yield. Soaking the sites of the planted yam sets with water during the dry season enhances early germination and digestion of the yam set before the arrival of the rains, thus permitting early development of yam tuber.

Other tubers should not be planted in the yam garden because tubers are heavy feeders and the harvesting of one will destroy the roots of the other and as a result produce a poor harvest. During the first two months of planting the yam sets it is essential to visit the farm garden weekly or every two weeks in order to direct the yam stem to climb the appropriate bamboos correctly. Only two stems are recommended from each yam set, unhealthy ones should be cut off so that two healthy tubers could eventually be produced.

Weeding
The weeding of the yam garden is done manually, with the hands only; the soil should not be disturbed. The essence of hand weeding is to protect the roots of the yam plant which are spread superficially all over the yam garden in the ridges and furrows. Most farmers are ignorant of the functions of the roots of plants consequently the hoe is always their companion in the farm during tilling and weeding. The machete should be used during weeding to remove tough and strong weeds. Weeding should be done as often as weeds appear, at least every two months. The grass thus removed should be put in the compost pit because they can easily become breeding ground for pests.

Mulching
Mulching is defined here as adding soil around the sweet yam stems on the ridge because its tubers grow upwards and thus they crack the soil above and if not covered the yam tubers will be hardened and damaged when exposed to sunlight and cold. Mulching is done by carrying soil from somewhere else out of the yam garden and putting it under the stem of the sweet yams. The species of yam that grow downwards (the Nkambe yellow) do not need mulching.

Application of other manure
Yam cultivation without traditional mulching could promote the rearing of domestic animals for their droppings thus small scale poultry, piggery, and even a cow for milking will provide excellent manure for the yam garden. However strict measures must taken during manipulation of animal droppings – hand washing before eating, wearing of gloves and masks.

Fighting pests
The most common pests observed are small yellow ants that feed just at the spot where the tubers are being formed sucking away most of the glucose from the leaves, this occurs from June at the beginning of tuber formation. The main stems should be monitored and the pests killed with appropriate pesticide.

Harvesting
In our yam garden without traditional mulching the yam tubers mature naturally after about 8 to 9 months, as from October. Harvesting of yams is done when the leaves of the yam are withered and dry.

Storage
The Nkambe yellow yam tubers should be covered with soil after harvesting because they easily get dry when exposed to the harsh cold and hot weather of the North West Region. The sweet yam tubers become hardened when exposed to cold; consequently they are immediately cooked and consumed after harvest.

In order to motivate farmers to practise yam cultivation without traditional mulching they must be provided the opportunity through training to know and understand the basic functions of the parts of the yam plant.
Roots:
- Absorb water and nutrients from the soil and send them to the leaves from which food is made
- The roots usually go the lowest spots in the garden (furrows) in order to absorb water since water always settle in the lowest areas of the garden.
- The major roots are the tubers; they store the food from the leaves in the form of starch.
- Each plant produces sufficient quantity of roots to suck up enough nutrients and water from the soil for the production of sufficient food by the leaves; therefore the reduction in the quantity of the roots by traditional mulching will have a disastrous effect on the yield of the yam; very small or no tubers will be produced.
Stems:
- The stems link the roots and the leaves
- Support the leaves.
- Transmit the nutrients and water from roots to the leaves.
- Transmit the food manufactured in the leaves to the tubers in the soil
- Staking is very essential to support and protect the stems and leaves; enables the stems to produce enough leaves for a good yield.
Leaves:
- The leaves manufacture the food in the form of glucose using the nutrients and water from soil, sunlight and carbon dioxide from the atmosphere by the process called photosynthesis.
- The food thus manufactured is sent through the stem to be stored in the tubers in the form of starch.
- Produce oxygen as an end product that we breathe.
- Staking exposes the leaves to sunlight.

Most farmers already practise the various phases of our yam cultivation as described above; we hope that all of them would sooner or later implement yam cultivation without traditional mulching with all its components.

CONCLUSION
Yam cultivation with hand weeding protects the roots of the yam plant, improves yam production, increases the availability of food, ameliorates nutrition and alleviates poverty in the family by increasing income from a good yield.

The significance of this article is to instil in the farmers a good awareness of the functions of the parts of the yam plant in order to enable them to adopt good and profitable farming practices such our yam cultivation with hand winding process with all its components.

The experience thus obtained from yam cultivation should be applied to other tubers such as cassava and cocoyam; and to all crops in general because more often soil is removed with hoes from the roots of crops such plantains, pineapples and sugar cane.

The attainment of the UN Millennium Goal 1: ‘Eradicate extreme poverty and hunger’ will be easily and quickly achieved through the education of the population especially at the level of families on the basic scientific knowledge of the functions of the parts of crops they cultivate in order to enable them improve on their farming skills. Mechanised farming may not be the immediate solution to a community in which all the families practise subsistent farming using primitive methods. The change of attitudes and habits can only be accomplished by working with the families in their communities through training and creating demonstration farms.

We pray that agriculture authorities should embrace and promote our yam cultivation techniques in order that our already industrious and conscientious farmers can produce more yams for the families and the world in order to achieve the yam cultivation revolution that we have initiated.

We have trained, on their request, some farmers who have seen our yam garden and yield on how to cultivate yams without traditional mulching. We advise that yam cultivation should be a family enterprise involving husband, wife and children; the husband will greatly help to stake the yams. Men should also plant yams because yam cultivation will provide a lot of employment and revenue to men.

With our method of yam cultivation with hand weeding, the ‘white Calabar’ yam would be introduced extensively in North West Region.

We recommend that our method of yam cultivation with hand weeding should be applied to the cultivation of tubers such as cassava and cocoyam.

The hoe should be the companion of the farmer during the tiling of the soil and making of ridges; while the hand is the natural companion of the farmer during weeding. The machete is used to remove tough weeds.

Our yam cultivation with hand weeding only with all its components is the key to solving the problem of unemployment, poverty and food insufficiency; deforestation of our virgin forest and environmental degradation.

We hope that one day we shall have a yam festival in the North West Region; why not in Cameroon!- by implementing yam cultivation with hand weeding.

This is our modest contribution to the wellbeing of humanity inspired by the Almighty God!
This article is published at the website: http://www.mfonfudaniel.blogspot.com/

We are grateful to all members of the Ba Mfonfu Family; we all grew up in the farm!
This research was sponsored by the authors.

REFERENCES

- Backyard Conservation customer, Mulching Backyard Conservation Features NRCS; www.nrcs.usda.gov/FEATURE/backyard/mulching.html
- Charles S. Wortman, Charles A. Shapiro, David D. Tarkalson, April 2006. Composting Manure and Other Organic Residues; www.ianrpubs.unl.edu/epublic/live/g1315/build.
- International Institute for Tropical agriculture (IITA), Clean Yam Production in Kayunga District Uganda; www.maendeleo-atf.org/Project-Profiles/profs_cidev.html
Marjan Kluepfel, Bob Polomski, Joey Williamson; Mulch, http://hgic.clemson.edu
- Ron DeHaan January 1996; Mulching for Erosion Control, www.gov.pe.ca/af/agweb/index.php3.
- Valerie SOPHIE, Use of mulching in agriculture. www.uom.ac.mu/faculties/foa/AIS/SIROI/SIROIWEBUK/Seychelles/Mamr/Agrinewsonline/Agrinews, Apr99.html
WHO, Primary health care, www.who.int/topics/primary_health_care/en
Wikipedia, Yam (vegetable), en.wikipedia.org/wiki/Yam_(vegetable)
Wikipedia, Composting, en.wikipedia.org/wiki/Composting.
Wikipedia, Mulch, 14 Nov 2008, en.wikipedia.org/wiki/Mulch
Wikipedia, Primary health care, en.wikipedia.org/wiki/Primary_health_care
Yam planting « tHe REd TaNk, 1 Oct 2007 theredtank.wordpress.com/2007/10/01/yam-planting

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