Continuous selective harvesting of soft stem vegetables to increase yield, reduce cost and labour

 

Continuous selective harvesting of soft stem vegetables to increase yield, maximize land use, reduce input cost and labour

The world demand for leafy vegetables growing on stalk or soft stems is rapidly growing. Despite the growing population, labour shortage has become a limiting factor for agricultural production and there is need to increase the amount of harvested vegetables at low labour input. One way to do this may be to consider harvesting the vegetable many times before it flowers and bear seeds. However, most western farmers have hardly explore this option of traditional selective harvesting that is geared towards increasing yield. This has left me pondering for a long time as I keep questioning myself …

Why do farmers harvest stalk leafy vegetables by uprooting them?

Ever since I traveled to the West, I have been wondering why farmers keep harvesting leafy vegetables by totally uprooting them. Once uprooted, the lifespan of the plants is over. Then they will nurse new seedlings again, tilled the soil, peg and plant afresh. What a waste of labour, time, inputs and harvest?

Rooted Amaranth (Green)

I grew up in Africa where I learned and practiced traditional farming practices from my grand-mums, parents and the entire community. Yes, we had a routine of going to the farm to cultivate our own vegetables and food crops every Saturday. A practice I enjoyed doing even after leaving the University of Buea and traveling to the West in 2003. In short, I am a proud farmer by birth and I don’t remember a year without growing my own organic food in my home garden. My family have been practicing subsistence farming and it is not by accident that I am passionate about farming.

How to harvest soft stem leafy vegetables

Most leafy vegetable grow on stalks that when harvested can develop new shoots from the remaining nodes on the stalk. In this case we harvest leaving about 2-4 nodes for new shoots to further develop, grow and spread out. Use a sharp knife and cut the vegetable just above 3 nodes on the rooted stalk. Within 4 days, you will see new lateral buds developing at the node. This may take about 10-14 days to fully grow into a broad leave stem vegetable ready for harvest.

So if you have a raised bed full with leafy vegetables, it is certain that all will not grow at the same rate, height or size. Normally these type of vegetables are usually planted closely (about 15-20 cm apart) to each other because only the vegetative growth is harvested as food. To ensure continuous harvest, you will need to employ the concept of selective harvesting.

Cut amaranth (Green)

Traditional selective harvesting practices

Selective harvesting is required for leafy vegetables that grow less homogeneously or are multi-annual. Selective vegetable harvesting allows us to harvest fresh vegetables weekly for a long period of time. Soft stem leafy vegetable like huckleberry (country njamajama), amaranths (green), bitter leaves and water leaves falls within this category. At Suzy-Farms we practice selective harvesting that enable us to harvest vegetables for about 2 months (at least 8 times) before they get mature. Once they are matured, they develop flowers and seeds. This is a sure indication that harvesting will soon come to a halt. But until then, these vegetables should be harvested by cutting the soft stem with a sharp knife. 

Within the bed of closely planted leafy vegetable, first harvest only the big matured ones. All small shoots vegetables should not be harvested. Leave these small ones to take advantage of the space created after the first harvest to further develop, spread out and growth bigger. Within a week, they must have grown bigger, matured and ready for harvest. At the same time the node left on the stems after the first harvest should have also developed young growing shoots. So by the time you carry out the second selective harvesting, this young shoots will also get enough space now to develop. This cycle may continue for 3 months with continues weekly harvesting. Please watch this video to understand how it works… Seeing is believing and believing is practicing. Click on our
youtube channel to watch how it is done in our home garden.

Bounty harvest of cut Amaranth from flower beds (companion planting)

Please make sure you grow organic, eat organic and live a healthy lifestyle. We live just ones! Don’t mess your life with unhealthy food. Start your own backyard garden as soon as possible so we can keep sharing information and good experiences. Grow your own food whenever possible and avoid frozen vegetable as much as you can. You can enhance your soil health by increasing the soil organic matter and also by practicing companion planting with beneficial synergies. This will also help to reduce pest and diseases while enhancing production. Please, make sure you harvest, cook and eat same day if possible. They are lots of vitamins and minerals in vegetables to nourish the body. These nutrients begins to reduce gradually from 8 hours after harvesting. Let your labour not go in vein. Harvest just when you are ready to prepare and eat. Watch this video here!!! 

Our Slogan: From Farm to Table. Yes! Let’s do it.  Experience it and share your story with us. Bingo!!! Those without gardens could buy fresh vegetables from organic stores or from your usual shop. However, stay away from frozen vegetable.

We shall be uploading videos soon on our YouTube channel. Subscribe to our channel, like, comment and hit on the notification button to keep up with update. Like our Facebook page and follow us on Instagram and Twitter 

Soil nutrients for optimal plants growth and production

Soil nutrients for optimal plants growth and production

Healthy and fertile soil needs adequate supply of nutrients for optimum plants growth. The major nutrients in the soil for plant growth are Nitrogen (N), Phosphorus (p) and Potassium (K) which make up the trio known as N-P-K. These nutrients are absorbed by the plants for root development (N & P), growth (N), flowering (P) and fruiting (K). Other important nutrients are Calcium (Ca), Magnesium (Mg) and Sulphur (S). Plants also need trace elements like Iron (Fe), Manganese (Mn), Zinc (Zn), Copper (Cu), Boron (B) and Molybdenum (Mo). These nutrients should be constantly replace else production will decline with decreasing amount of soil nutrients. These nutrient must be balance. A deficiency of one nutrients cannot be compensated by the surplus of the other.

Essential soil nutrients for optimum plants growth

The concept of limiting factor states that plants growth is always controlled by the mineral nutrients in shortest supply, even when sufficient quantity of the other nutrients exist. Imagine a wooden bucket with staves of different length. If water is filled in the bucket, it can be filled only to the height of the shortest stave – the limiting factor. In nature, N is almost always limiting in plant growth.

Liebig's law of limiting factor

Major element (N-P-K)

Nitrogen (N): Nitrogen is found in plant cells, proteins, hormones and chlorophyll. It is a very essential element in plant growth. The main source of soil N is from the atmosphere. Legumes fix atmospheric nitrogen in their roots thereby helping to convert atmospheric N into soil nitrate that plants can easily absorb. Dark soils usually contain more N than light brown soil. Heavy rain usually leached out nitrate from the soil, so it should be added in small amount that plant can effectively use it – preferable in organic form like composted manure which release the nitrate slowly.

Phosphorus (P): Phosphorus stimulates early root development, photosynthesis and plant growth. It also transfer energy from sunlight to plants and hasten maturity of plants as it helps plant to produce flowering site and produce large buds. Manure contains P especially grain-fed animal manure like chicken manure.

Potassium (K): Potassium helps plant to resist diseases and increase flowering and fruit production. It enhance strong root growth, water intake and helps to form and move starch, sugar and oil in plants. It enhance plants vigour, disease resistant capacity and yield. Cassava and bananas are big potassium users.

Secondary nutrients (Ca-Mg-S)

Calcium (Ca): Calcium is vital for healthy roots and leaves development. It helps produce strong cells and root walls.

Magnesium (Mg): Magnesium is a key component of chlorophyll which makes leaves green. Chlorophyll is vital for converting sun’s energy to food for the plant in a process call photosynthesis. Magnesium also helps with production of carbohydrates and sugars to enhance flowering. Deficiencies occur mainly on sandy acid soils in high rainfall areas.

Sulphur (S): Sulfur is a major constituent of amino acids in plant proteins. It is involved in energy-producing processes in plants. It helps produce chlorophyll and play a vital roles in foliage and root development. It is responsible for many the flavour in many plants like onions, cabbage, garlic etc. Sulfur deficiency is not a problem in soils high in organic matter.

Micro- nutrients: These are trace elements that are needed in small quantities for healthy plant growth

Iron (Fe): Iron regulate and promote growth, components of enzymes, essential for chlorophyll synthesis, photosynthesis

Manganese (Mn): Manganese helps with photosynthesis, chloroplast formation, cofactor in many plant reaction, activate enzymes

Copper (Cu): Copper is an essential element of plant enzymes, involved in photosynthesis

Zinc (Zn): Zinc supports the production of plant hormones and auxins activity which are responsible for stem elongation and leaf expansion

Boron (B): Boron enhances the formation of cell wall in growing tissues. Important in sugar transport, cell division and amino acid production

Molybdenum (Mo): Needed by soil organism and bacterial in the nodules of legumes to convert atmospheric nitrogen into soluble nitrogen compounds in the soil like nitrate. It is vital in proteins formation from nitrates.

Chlorine (Cl): Used in turgor regulation, aid photosynthesis, resist diseases

Symptoms of nutrients deficiency in Plants 

Plants need the right combination of nutrients to live, grow and reproduce.  They often show symptoms of being unhealthy when they lack these nutrients. Below are some of the symptoms of nutrients deficiency that can be identify on the plant. 

Nutrients imbalance

Too little or too much of any one nutrient can cause problems of nutrients imbalance. So it is good to fertilize lightly and monitor or you test the soil before adding much fertilizer. Nutrients interacts with each other either synergistically to increase the uptake of one another or antagonistically to fight each other and lock each other out. Check the soil to make sure nutrients are not locked out of the plants and building up in the soil before adding supplemented nutrients. The Mulder’s chart specifically shows which nutrients in the soil increases (synergy) or decreases (antagonism) availability of the other nutrients in the soil.

Important plant nutrients across different growth stages 

Since different nutrients have different functions, the nutrient needs of a plant also changes from propagation to early vegetation, late vegetation to flowering. It begins with strong root development which require N. At early vegetation stage, the need of N and K increase to produce more leafy growth, horizontal branching and tight internodes. When flowering time arrives, N levels drops off and P intake increases slightly as the focus now is to produce dense, potent flowers. When the fruits are about to ripe, the need for K start increasing.

We recommend that you you stick to a N:K ratio of 5:4 during vegetative stage and drop it gradually to 2:3 during flowering. Research have shown that too much phosphorus during flowering may leads to many smaller nuts, but not bigger nuts and the need for P is pretty low throughout plant's life cycle. The Ca:Mg ration should be kept at 3:1 to balance charges and enhance uptake of plant nutrients. 

Change of nutrients requirement over different plant stages

In our next write-up, we shall discuss how to add these nutrients to the soil in naturally. We shall be uploading videos soon on our youtube channel. Subscribe to our channel, like, comment and hit on the notification button to keep up with update. Like our facebook page and follow us on instagram and twitter 

Polyculture for pest control, high yield & food diversity

 Polyculture - alley, strip, cover, inter, mixed or three sister cropping systems

Polyculture is an agricultural system were multiple crops are planted on the same piece of land to provide crop diversity which mimic the diversity of natural ecosystems. This does not only provide food, but sustain life as a whole. As opposed to raising single crop/animal (monoculture), polyculture is raising more than one species of plants or animals at the same time and place. Polyculture is an old system of farming which is still carried out in sub-Sahara Africa and has regained popularity today because of its environment and health benefits. It is a sustainable form of agriculture because of its ability to control pests, weed and diseases without major chemical inputs. There are different types of polyculture systems such as intercropping, cover-cropping and alley cropping. The type of polyculture carried out depends on the types of plants grown, the spatial distribution and the time they spend growing together. The type of plants or animals that can be raised in a polyculture system has no limit.

Three sister crops (Maize, beans and pumpkin)

Intercropping or mixed cropping – This occurs when two or more crops are planted together e.g legumes and cereals mixtures. The legumes fix atmospheric nitrogen into the soils at its root noddle in a process called nitrogen fixation. This soil nitrogen acts as fertilizer for the other plants and therefore eliminates the need for man-made fertilizers. A typical example is the ‘three sister crop’ system of planting maize, beans and squash (e.g pumpkin) in a group to provide mutual benefits to each other. The maize provides support for the beans to grow on, the beans provide nitrogen to fertilize all the plants while the squash suppresses the weeds. These crops thus sustain each other with little or no human intervention.

Cover cropping: - This is when a crop is grown alongside another plants that is not a crop e. grass & legumes. Cover crops can help to prevent erosion, suppress weeds, improve water retention or fix nitrogen. It can also be called weedy culture if the non-crop element is a weed.

Strip or alley cropping

Strip or alley cropping: - This involves growing different crops in alternating rows. Though it doesn’t involve a complete mix of the plants, it also prevent soil erosion and aid nutrient cycling. 

Permaculture: - This is a polyculture of perennial plants such as cocoa, coffee, timber, fruit trees etc. This system increases soil fertility, decreases soil erosion, conserve soil nutrient and increase soil organism and water retention. Agroforestry is a popular form of permaculture where trees and crops are grown together. The trees provide shade and organic nutrients when they share off their leaves and also provide extra commodities like timber, medicine, firewood etc. Shade loving crops like coffee and cocoa are well suited within such a system.

Advantages of polyculture

Pest and disease control: - Pest are less predominant in polyculture due to crop diversity. Specialized pest that prefers a concentration of a single crop type often gets confused as they find it difficult to locate a favorable host in a polyculture. Common general pest moves from one plant to another within a polyculture system to the surrounding environment because they look alike, thereby reducing the effect on a particular crop. This diversity of plants attracts natural enemies or predators which help to further suppress pest population without causing harm to the plants. Different plants are susceptible to different diseases so the spread of diseases can be contained in polyculture.

Weed control: - the high density of plants reduces available space, sunlight, water and nutrients for weed to develop as resources are fully utilized by crops. The few that do grow can host arthropods (pest enemies) that are beneficial to other crops.

 Sustainability: -

A bunch of plantains at Suzy-Farms

A polyculture system doesn’t depend on pesticide, but can be boosted with minimal use of organic fertilizers as diverse plants are planted together. This greatly reduce eutrophication of fresh water, hence good health and wellbeing. Reduce tillage conserves microbes and soil nutrients. This saves money as farmers can grow multiple crops and animals on same piece of land with little or no machinery. It increases local biodiversity which attract different pollinators, hence increase pollination and fruits harvest. Polyculture addresses human subsistence needs because food security doesn't just depends on quantity, but on diversity and quality of available food. Polyculture is diverse in nature and provides both nutritional and economic resilience  because if one plant fails, the other crops may support the household with food and income.

Polyculture is more effective when the diverse plant species have distinct biological needs such as absorbing different nutrients and requiring different amount of sunlight (no competition). Our modern lifestyle is negatively impacting our land and ecosystems. Restoring these systems will lead to food abundance to support human life and culture as well as restore the ecosystems. It is our duty to secure a rich permaculture for future generation. So let’s do it...

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