Scalability of Adaptation strategies to drought stress: the case of drought tolerant maize varieties in Kenya

Figures & data

Figure 1. Flow chart showing scaling strategy for drought tolerant maize varieties.

Figure 2. Flowchart linking DTMV awareness, seed access and affordability variables.

Figure 3. Map showing survey sites in Kenya.

Table 1. Distribution of Sample households.

Makueni	Machakos	Embu	Thara Nithi	Kakamenga	Busia	Bungoma	Trans-Nzoia	Total
90	90	90	90	125	90	60	45	680

Table 2. Descriptive statistics by the adoption status of DTMVs.

Variables	Full Sample (n = 680)	Adopters (n = 175)	Non-adopters (n = 505)	Mean difference
Household size (No.)	5.35	6.05	5.12	−0.925***
Gender (1 male, 0 female)	0.69	0.74	0.68	−0.061
Age (years)	53.16	48.80	54.67	5.87***
Years of education	7.66	7.87	7.59	−0.28
Farm size (ha)	0.98	0.97	0.98	0.01
Received information on new varieties (%)	40.1	49.7	36.8	−12.9***
Sources of information (%)
- Government	6.0	6.9	5.7	1.1
- Private extension	1.5	1.1	1.6	0.5
- NGO	6	10.9	4.4	6.5***
- Demos and field days	9	15	7	8**
- Input suppliers	9.9	13.7	8.5	5.2**
- Other farmers	21.5	28	19.2	8.8***
- Electronic Media	19.9	17.7	20.6	2.9*
Income Status
- Able to build savings	2.4	2.9	2.2	0.7
- Able to save little	16	15	16	0
- Income equal expenses	32.1	29.1	33.1	4
- Draws from savings	34.3	41.1	31.9	−10
- Borrows to meet expenses	15.2	10.9	16.7	5.8
Membership in group (%) (1 = yes, 0 = otherwise)	78	73	80	7*
Distance to the market (km)	3.66	3.97	3.55	−0.41
Had dry spells in 2018 (%) (1 = yes, 0 = otherwise)	3.3	3.6	3.2	−0.29
Households that own livestock (%)	92.4	93.7	91.9	−1.9
Households are aware DTMVs (%)	37	100	15	−85***
Households have access to seed (%)	36	85	12	−73***
Households have access to affordable seed (%)	34	75	10	−65***

*Imply that difference between adopters and non-adopters is statistically significant at 95% level (t-tests are used for differences in means)

Figure 4. DTMV awareness and adoption by county, Kenya in 2018.

Table 3. Probit estimates of the determinants of DTMV exposure, seed access, and seed affordability.

Variable	Model 1 (exposure)	Model 2 (exposure-access to seed)	Model 3 (exposure-access to seed at affordable price)
Household size (No.)	0.008	0.010	0.01
Gender (1 = Male; 0 = Female)	0.012	0.009	0.01
Age of head of household (Years)	−0.004**	−0.004*	0.00
Years of education	0.018**	0.017**	0.016**
Distance to Market (km)	0.036	0.037	0.02
Farm size (ha)	0.018	0.014	0.01
Farm demonstration in the household village	0.072	0.062	0.09
Information sources (Reference group: no information received)
- Government extension	0.095	0.113	0.03
- Non-government extension	0.063	0.070	0.08
- Input suppliers	0.058	0.071	0.08
- Other farmers	−0.01	0.02	0.02
- Electronic Media	0.181**	0.181**	0.151*
Income status (Reference group; insufficient income need borrowing)
- Able to build savings	0.121	0.2	0.28
- Able to save a little	0.237*	0.316**	0.366***
- Expenses equal savings	0.245**	0.278***	0.319***
- Draws from savings	0.184*	0.236**	0.291***
Busia	0.837***	0.850***	0.855***
Machakos	0.067	0.034	0.00
Embu	0.092	0.089	0.03
Tharaka Nithi	0.484***	0.447***	0.431***
Kakamega	0.674***	0.653***	0.617***
Bungoma	0.694***	0.692***	0.663***
Trans Nzoia	0.706***	0.721***	0.732***
N	679
Aic	585.935

*p < 0.10, **p < 0.05, ***p < 0.01.

Table 4. Scalability of DTMVs based on predicted potential adoption rates.

	Parameter with awareness-unconstrained			Parameter with awareness–access –unconstrained			Parameter with awareness–access- affordability-unconstrained
	Est.	S.E	Z	Est.	S.E	Z	Est.	S.E	Z
ATE-Corrected population estimates
Predicted adoption rate in full population (ATE)	0.522*	0.050	10.50	0.564*	0.053	10.59	0.597*	0.059	9.9
Predicted adoption rate in treated subpopulation (ATT)	0.690*	0.026	26.32	0.718*	0.026	27.73	0.754*	0.025	29.12
Predicted adoption rate in untreated sub-population (ATU)	0.424*	0.072	5.90	0.480*	0.076	6.300	0.518*	0.048	6.07
Joint treatment and adoption rate (JTA)	0.256*	0.010	26.32	0.256*	0.009	27.73	0.256*	0.008	29.12
Population adoption gap (GAP)	−0.266*	0.045	−5.900	−0.309*	0.049	−6.30	−0.335*	0.055	−6.07
Population selection bias (PSB)	0.167*	0.042	4.020	0.153*	0.045	3.390	0.155*	0.05	3.183
Observed sample estimates
Rate of treated ($N_e/N$)	0.371*	0.018	20.00	0.356*	0.018	19.38	0.340*	0.018	18.70
Adoption rate ($N_a/N$)	0.256*	0.016	15.28	0.256*	0.016	15.28	0.256*	0.016	15.28
Adoption rate among the treated subsample	0.690*	0.045	15.28	0.719*	0.047	15.28	0.743*	0.049	15.28

*Denote statistical significance at 5% level.

Table 5. ATE corrected marginal effects of the determinants of adoption of DTMVs under heterogeneous seed access and information exposure.^a

Variable	Model 1 (exposure)	Model 2 (exposure-access to seed)	Model 3 (exposure-access to seed at affordable price)
Household size (No.)	−0.020	−0.026	0.034*
Gender (1 = Male; 0 = Female)	0.1597*	0.187*	0.193*
Age of head of household (Years)	−0.004	−0.004	−0.006*
Years of education	0.003	0.001	0.002
Distance to Market (km)	0.033	0.041	0.076
Farm size (ha)	−0.045	0.056	0.045
Farm demonstration in the household village	−0.015	−0.029	−0.051
Information sources (Reference group: no information received)
- Government extension	−0.024	−0.050	0.020
- Non-Governmental extension	−0.015	−0.02157	−0.044
- Input supply	0.073	0.0566	0.061
- Other farmers	−0.015	−0.0721	−0.126
- Electronic media	−0.142	−0.017117	−0.192
Income status (Reference group; insufficient income, need to borrow)
- Build savings	0.287	0.1860	0.035
- Save little	0.024	−0.1090	−0.278
- Expenses equal savings	0.145	0.0785	−0.076
- Draw from savings	0.212	0.1138	−0.040
Busia	0.426***	0.400***	0.411***
Machakos	−0.203	−0.147	−0.076
Embu	−0.343	−0.371	−0.293
Tharaka Nithi	−0.001	0.028	0.057
Kakamega	0.174	0.212	0.254
Bungoma	0.159	0.178	0.232
Trans Nzoia	0.2622	0.240	0.227
N	679	231	679
Aic	655.83	262.37	575.39

*p < 0.05; **p < 0.01; ***p < 0.001.

^aWe only present results of the ATE-corrected adoption models for exposure, seed availability and access to seed at affordable prices.