Good agronomic practices are required for cassava as a basic and mostly consumed food in Nigeria. A sustainable high yield of cassava is essential to attain food security. Yet, there is not enough supply to meet the nation’s demand. Most cassava farmers still struggle with its production cost, lack of adequate technology to reduce labour, and poor access to land (lack of enabling environment).
The struggle among cassava farmers is because they are not informed or have biases about the best practices that guarantee an increased yield with minimal cost. As a result, there is still a continual use of old stem varieties that are susceptible to diseases, and affected by harsh weather conditions. This has led to a low yield of 8-11 tonnes per hectare (i.e. 2.5 acres or 15 plots of land). So, research and field experience by a team of experts have shown that sustainable practices are requirements and beneficial to achieving increased cassava yields. Based on this, any farmer in Nigeria who desires an improvement in their agricultural endeavours is encouraged to adopt GAP (Good Agronomic Practices).
Good Agronomic Practices (GAP) For Maximizing Cassava Yields
Cassava, a vital root crop, is mostly consumed in Nigerian homes. However, achieving high yields while keeping the soil healthy for sustainable farming might seem unrealistic. But, by following these good agronomic practices, you can cultivate a thriving cassava farm that delivers high yields while safeguarding the soil fertility for future harvests;
1. Land Citing
Cassava grows well in well-drained, aerated fertile soil with a PH range of 5.5 to 6.5 and it is essential to select a site with good sunlight exposure and minimal risk of waterlogging. This is because cassava roots can rot in swampy areas or water-logged conditions. If you have any doubts, look out for a land with earthworm cast or Awolowo plant as they are great indicators of a site best for cassava production.
2. Land Preparation
Clearing weeds, plough, and ensuring good soil structure through ridging or mounding are proper land preparation methods, but following these specific guidelines can significantly enhance your cassava yield:
- If a land is fallowed for years, cut the trees and remove stumps.
- Then, apply a pre-plant herbicide of your choice (A 250cl in a 16-litre knapsack. For a hectare of land, it would take 4-5 litres in 16-20 loads of the 16-litre knapsack).
- Allow 7-10 days after application to have weeds die and decay back into the soil.
- Land tillage is discouraged in order not to disrupt the soil ecosystem.
- However, the cassava crop requires loose soil to allow the roots to properly and adequately penetrate for good yield, so make mounds or ridges. But ridges are preferable since they bring about orderliness in the farm operation.
3. Seed Selection
A successful cassava crop is tied to the foundation of using healthy and disease-free or resistant planting materials. Farmers should choose stems (cuttings) from several improved varieties (TME 419, Vit A, TMS/98/0505, Imo Best, etc.). 100+ new varieties have shown good yield potential in local conditions like TME419 which has a high starch content and dry matter. However, consider and select fresh and healthy stems with no wounds on the body of the stem as this ensures a strong start for the crop and reduces the risk of early losses.
4. Stem Handling
Cut 20 – 25cm (5-8 nodes minimum) length for each stem for planting and do so on a soft soil surface. If the stem is dry, pour water to soften it and use a sharp knife or machete while cutting. Don’t tie more than 50 stems together and while putting it down after carrying it to a location for use, gently drop it to avoid rubbing or causing damage to the nodes.
5. Planting
Cassava planting is best done at the beginning of the rainy season, which ensures they have sufficient moisture to establish. While planting the stems, do not bury or keep them positioned straight in the ground to avoid losing the tubers during harvest. Slightly slant (at angle 45) 2/3 of the stem length into the soil and the remaining 1/3 should be visible on the soil surface for sunlight and photosynthesis.
6. Spacing
Maintaining optimal spaces between each cassava stem and the other is essential to avoid competition for growth nutrients. A spacing of 1 meter between plants in rows and 0.8 meters between those rows is generally recommended for healthy or maximum yield. If your prepared soil is in ridges, give a space of 1M X 1M for one stem. For moderate mounds, plant one stem on a mound. Then, if it is a large mound or heap, plant 2 stems on each mound or heap. This gives good feeding space to the plants.
7. Weed Management
Weeds compete with cassava for nutrients and water, thereby reducing yields. Hoeing or mulching though are effective weed control methods, herbicides application produces great results and should be used according to the recommended guidelines as follows:
a. Pre-Emergence Herbicide:
Immediately after planting (not more than 48 hours) cassava stems, apply pre-emergence herbicide to seal the soil surface like a blanket, which kills all the weed seeds through denial of sunlight. No one is expected to match on the treated farm for 7 days. If you practice mixed cropping, you can only plant other crops after the 7 days (one week).
b. Post-Emergence Herbicide:
This should be done 3 months (12 weeks) after planting, and follow product direction for application use. During spraying, avoid touching the grown cassava body with herbicide.
8. Fertilizer Application
Chemical use for farm operations mostly has wrong biases but, there is no research evidence of anyone who has died from food grown with Fertilizer. However, when not properly applied or done in excess, there are traces of it found in our water bodies after rain outpours.
Cassava requires nutrients like nitrogen, phosphorus, and potassium (NPK) for robust growth, a soil test must be done first to determine specific nutrient needs or in what proportions to apply. Organic Fertilizers such as compost or manure can improve soil structure and fertility, while balanced chemical Fertilizers supplement macro and micronutrients as required.
The best Fertilizers for cassava are now NPK 20-10-10, NPK 15:15:15, and NPK 12:12:17. Apply between 6-8 weeks after the date of planting. Use a small matchbox to measure the specific quantity (20g) and apply it to one stem per stand using the point application or circle method (which is most effective). The amount of Fertilizer used matters because an overdose destroys the soil.
9. Monitoring
A good practice should be checking and replacing worn-out cassava stems after two weeks or a month of planting them. Then, regularly monitor your farms for any stranger elements, rodents, thieves or whatever is not required on the farm. Guard your cassava farm jealously against intrusions by building structures or setting up systems that scare things away and secure the site.
10. Harvest
A cassava farm is mature for harvest between 9-12 months. Timely harvesting at the appropriate maturity stage prevents deterioration and loss. You may process for consumption, and sell to processors directly or through aggregation at prevailing price.
11. Stem Preservation after Harvest
This is important to reduce farmers’ expenses on purchasing cassava stems for the next planting. After harvest, assemble the stems and arrange them in 50 stems per bundle. Dig trenches around shaded areas, pour enough water, and then stack the stems in the trenches in a standing position. As long as the stems stay there, regularly observe and pour more water, do not allow them to dry. They can be preserved in this manner for 3 months.
12. Cassava Production as Business
When you want to produce cassava for sale or processing for income generation, start from at least one hectare, and ensure implementing the good agronomic practices as stated above.
Conclusion on Cassava GAP in Nigeria
By implementing these Good Agronomic Practices to a reasonable extent, high yields of cassava would be sustainably achieved by farmers, alongside preserving the environment and enhancing food security in Nigeria. The resilience and economic importance of cassava make it a cornerstone of agriculture, and coupled with responsible farming practices, we can contribute more to livelihoods and national development like future generations benefitting from this valuable crop for years to come.
Notwithstanding, farmers are encouraged to attend training to stay informed about innovations and collaborate with agricultural extension services as agronomic practices evolve with research and changing environmental conditions.
