Growing Dolichos in Garissa

Soil suitability analysis based on Garissa's nutrient profile

Quick answer

Generally not ideal — Garissa is poorly suited to Dolichos. Garissa's soil (pH 7.96, alkaline) gives Dolichos a suitability score of 1/100. Match fertilizer to Garissa's nitrogen and phosphorus levels for the best result.

Garissa County is a challenging environment for Dolichos (soil-match score 1/100) and will need significant amendment before planting. At an average pH of 7.96 the soil sits above Dolichos's preferred 5–7.5 range, which can limit uptake of phosphorus and micronutrients. Nitrogen (0.61 g/kg), phosphorus (37.7 mg/kg) and potassium (407 mg/kg) all meet Dolichos's requirements, so a maintenance fertilizer programme is enough. The county's predominantly sandy soils suit Dolichos, which favours sandy loam. Garissa receives approximately 250 mm/year — well below Dolichos's minimum of 400 mm — so supplemental irrigation would be essential for this crop. On ShambaIQ's soil-match model, Dolichos is the #71 soil match of the 106 crops we assess for Garissa County. Dolichos's full potential is about 600 kg/acre (~KES 72,000/acre at KES 120/kg), but at Garissa's 1/100 suitability a realistic target here is closer to 8 kg/acre (~KES 960/acre) unless the constraints above are addressed.

Better matched to Garissa's soil: Sisal, Aloe Vera, and Green Grams — each scores higher on the same soil.

1Suitability score

Soil & climate match

FactorGarissa soilDolichos needsStatus
pH7.9657.5Adjust
Nitrogen0.61 g/kgmin 0.5 g/kgOK
Phosphorus37.7 mg/kgmin 6 mg/kgOK
Potassium407 mg/kgmin 100 mg/kgOK
Rainfall250 mm400–1,000 mmLow
Altitude200 m1,000–2,100 mLow

Planting calendar

Long Rains

Month 1
Sowing & DAP Basal Fertilizer (NO CAN — nitrogen fixer)
Month 2
Weeding & Vine Support if needed
Month 3
Pod Fill & Harvesting

Short Rains

Month 1
Sowing & Basal Fertilizer (no CAN)
Month 2
Weeding & Pest Scouting
Month 3
Harvesting & Seed Drying

Dry Season

Month 1
Post-Harvest seed storage
Month 2
Land Resting (N benefit remains in soil)
Month 3
Seed Selection & preparation

Top dressing guide

Product
None
Timing
None required
Instruction
Dolichos (njahi) fixes its own nitrogen through rhizobia. Do NOT apply CAN — it suppresses nodulation and reduces yield. A starter dose of phosphorus at planting is enough.
Bags per Acre
0

Recommended seed varieties

Njahi BlackMedium/Highland
KALRO · 90-120 days · 8-12 bags/acre
Black hyacinth bean (njahi); popular in Central Kenya; high protein; nitrogen-fixing soil improver.
DL 1002Dryland/Medium
KALRO · 90-110 days · 7-11 bags/acre
Improved dual-purpose lablab; grain and fodder; tolerant to drought and low fertility.
Eldoret BrownMedium
KALRO · 100-130 days · 8-13 bags/acre
Brown-seeded selection; vigorous; good for intercropping with maize.
ELDO-KT Black 1Medium/Highland 10-2000m
University of Eldoret · 135-150 days · 14-22 bags/acre
Black seeded; short cooking time; uniform maturity.
ELDO-KT CreamMedium/Highland 10-2000m
University of Eldoret · 120-135 days · 16-25 bags/acre
Cream seeded; early maturity; good flavor; short cooking time.
ELDO-KT Black 2Medium/Highland 10-2000m
University of Eldoret · 120-135 days · 16-29 bags/acre
Black seeded; medium maturity; robust growth.

Economics

Market priceKES 120/kg
Expected yield in Garissa8 kg/acre
Estimated revenueKES 960/acre
Adjusted for Garissa's 1/100 suitability. Under ideal conditions Dolichos can reach 600 kg/acre (~KES 72,000/acre) — attainable here only after the climate and soil constraints below are addressed.

Preferred textureSandy Loam

Fertilizer prices

DAP
KES 3,500(6,500)
CAN
KES 2,875(5,700)
NPK 17:17:17
KES 3,275(5,600)
Urea
KES 3,500(5,500)
Lime
KES 1,500(1,800)

Green = subsidized · (Commercial) per 50kg bag