Cultivation of Cash Crops: Turning Theory into Profit

Hello future farmers! This chapter is where we move from understanding soil and plant growth (Sections 2 and 3) to actually producing valuable crops. We are focusing on Cash Crops—crops grown specifically to be sold for profit, rather than just for feeding the farmer's family. Understanding the detailed steps of cultivation is vital for ensuring high yields and profitability.

Let's dive into the practical details of producing successful crops!

1. Defining and Classifying Local Crop Types (Syllabus 4.2a)

Before detailing one specific crop, you need to be able to identify the main categories of crops found locally in your region. These are often categorized by what part of the plant is harvested and sold:

A. Main Crop Categories and Products

1. Cereals (The grain or seeds are the main product):
These are staple foods globally. They are grasses cultivated for their edible grain.
Examples: Maize (Corn), Wheat, Rice, Sorghum.

2. Legumes (Produces seeds in pods, valuable for protein and fixing nitrogen in the soil):
These crops are crucial both as food and for improving soil fertility.
Examples: Beans, Peas, Groundnuts (Peanuts), Soybeans.

3. Roots and Tubers (The swollen root or stem stores food):
These are important sources of carbohydrates.
Examples: Cassava (Root), Irish Potato (Tuber), Yam (Tuber), Sweet Potato (Root).

4. Edible Fruits and Vegetables (Often high-value crops, requiring careful handling):
This category includes soft fruits and market garden vegetables.
Examples: Tomatoes, Bananas, Mangoes, Cabbages, Oranges.

Key Takeaway: Identifying the type of crop (cereal, legume, etc.) tells you immediately what conditions it generally prefers and how it should be harvested and stored.

2. Detailed Cultivation of a Named Cash Crop: MAIZE (CORN) (Syllabus 4.2b)

We will use Maize as our detailed example, as it is a globally important cereal cash crop. Remember, you must be ready to describe *one* crop in this level of detail for your exams.

2.1 Soil and Climatic Requirements

Maize needs specific conditions to thrive and produce a high yield:

Soil Requirements:

  • Maize performs best on deep, fertile, well-drained loam soils.
  • The soil should have a pH between 5.5 and 7.5 (slightly acidic to neutral).
  • Since maize is a heavy feeder, the soil must be rich in organic matter and essential nutrients, especially Nitrogen (N).

Climatic Requirements:

  • Temperature: Maize is a warm-weather crop. It requires high temperatures, ideally between 20°C and 30°C, during the growing season. Frost is extremely damaging.
  • Rainfall: It needs high, well-distributed rainfall (e.g., 500 mm to 1000 mm) during planting and the flowering/tasselling stage. Water stress during flowering severely reduces yield.

2.2 Soil Preparation, Sowing, and Spacing

Proper land preparation creates an ideal seedbed, removes weeds, and improves soil aeration and water infiltration.

Soil Preparation (Linking to Section 4.1):

  1. Primary Cultivation: Use a mould-board plough (or digging by hand) to turn over the soil, burying weeds and crop residues. This should be done early, before the rains.
  2. Secondary Cultivation: Use a harrow or rake to break up large clods and create a fine, firm seedbed. A fine seedbed ensures good contact between the seed and the soil for effective germination.

Sowing Time and Method:

  • Time: Sowing must occur immediately after the first effective rains to make the best use of the moisture and ensure the crop matures before the dry season starts.
  • Method: Maize is typically planted by hand (dibbling) or using a planter in rows (row planting). Row planting is essential for later mechanised operations like weeding and fertilising.

Choice of Suitable Cultivars:

  • A cultivar (or variety) is a specific type of crop chosen for certain desirable traits.
  • Farmers choose cultivars based on their local climate and needs, such as: high yield potential, resistance to common local diseases (e.g., maize streak virus), early maturity (if rainfall is short), and drought tolerance.

Seed Rate and Spacing:

  • Seed Rate: This is the amount of seed used per unit area (e.g., kg/hectare). It determines the plant population.
  • Spacing: Typical spacing for maize might be 75 cm between rows and 30 cm between plants within a row.
  • Why Spacing Matters: Too close, and plants compete intensely for light, water, and nutrients (lower yield). Too far apart, and land is wasted (lower yield). Proper spacing maximizes light interception and nutrient use.

Quick Tip for Spacing: Think of spacing as giving each plant its personal supply of resources! If they are too crowded, they fight for food.

2.3 Crop Management: Fertiliser, Pests, Weeds, and Diseases

Efficient management protects the plant's health and boosts the final yield.

Rates of Application of Fertiliser and Manure:

  • Manure/Organic Fertiliser: Applied before planting during soil preparation to improve structure and provide slow-release nutrients.
  • Inorganic Fertilisers: Maize requires high levels of N, P, and K.
    • Basal Dressing: Phosphorus (P) and some Potassium (K) are applied at planting or shortly after, to help with root establishment.
    • Top Dressing: Nitrogen (N) is applied later (e.g., 4 to 6 weeks after germination) because it is quickly leached away. Nitrogen boosts vegetative (leaf) growth.

Prevention and Control of Common Pests, Weeds, and Diseases:

  • Weeds: Compete heavily with young maize for nutrients and water. Control methods include mechanical (hoeing/inter-row cultivation), cultural (crop rotation), or chemical (herbicides).
  • Pests: Common maize pests include the Maize Stalk Borer (boring pest) and Aphids (piercing/sucking pest). Control involves monitoring, use of appropriate insecticides, and cultural methods like destroying old stubble.
  • Diseases: Fungal diseases like Maize Rust are common. Control includes planting resistant cultivars and using appropriate fungicides.

2.4 Harvesting, Yield, and Storage

The final stage requires careful timing to maximise quality and minimize losses.

Recognition of Crop Maturity:

  • Maize is mature when the husks turn yellow and dry, and the kernels become hard and develop a 'black layer' where they attach to the cob.
  • The moisture content needs to be low enough (e.g., 20-25%) before harvesting, otherwise spoilage will occur quickly.

Harvesting and Yield:

  • Harvesting is often done by hand, or by combine harvesters on a large scale.
  • Yield is the total weight of the harvested product per area (e.g., tonnes/hectare). A good yield reflects efficient cultivation practices.

Storage:

  • Before storage, the grain must be dried to a safe moisture content (usually 13–14%) to prevent mould growth.
  • Grain is stored in silos, granaries, or bags. Storage facilities must be clean, dry, and protected from storage pests like grain weevils and rats.

2.5 Record Keeping: The Farmer's Diary

Record keeping is often overlooked but is essential for successful farm business management. Records help the farmer make informed decisions and track profitability.

What to Record (The Diary of Events and Production):

  1. Input Costs: Record every expense: cost of seed, fertiliser, chemicals, fuel for tractors, and labour wages.
  2. Field Activities (Diary of Events): Record the dates of all operations: ploughing, planting, weeding, fertiliser application, and spraying.
  3. Yield Data: Record the total yield harvested from each field (e.g., 5 tonnes).
  4. Sales Records: Record the price received and the buyer.

Why Keep Records?

Records allow the farmer to calculate the cost of production and identify which fields or practices were most profitable. They help predict future needs and justify why certain practices (like using more fertiliser) increased or decreased the profit margin.

Did you know? Accurate records are also essential if a farmer wants to apply for a loan, as they prove the farm is a viable business!

QUICK REVIEW BOX: The 10 Steps for Crop Cultivation (Maize Example)

| Step | Action (Maize) | |---|---| | 1. Requirements | Ensure deep loam soil, 20-30°C temperature, adequate rain. | | 2. Soil Prep | Plough, then harrow to create fine, firm seedbed. | | 3. Sowing Time | Plant at the start of the rainy season. | | 4. Cultivars | Choose high-yielding, disease-resistant variety. | | 5. Spacing | Use precise row planting (e.g., 75 cm x 30 cm). | | 6. Fertiliser | Basal dressing (P/K) at planting; Top dressing (N) during growth. | | 7. Pests/Weeds | Control stalk borer and weeds using cultural/chemical methods. | | 8. Maturity | Harvest when husks dry and kernels form a black layer. | | 9. Yield/Storage | Record yield; Dry grain to 13% moisture; Store away from weevils. | | 10. Records | Maintain a diary of all dates, costs, and production data. |