Table 3 Factors affecting adoption of inorganic fertilizer (craggit models).
Explanatory variables | Without endogenous variables | With endogenous variables | ||
|---|---|---|---|---|
Hurdle 1: probability of adoption | Hurdle 2: log of fertilizer used (kg/ha) | Hurdle 1: probability of adoption | Hurdle 2: log of fertilizer used (kg/ha) | |
Head’s gender (female = 1) | − 0.382*** (0.142) | − 0.002 (0.081) | − 0.341** (0.145) | 0.016 (0.081) |
Head’s age (year) | 0.004 (0.004) | 0.002 (0.002) | 0.004 (0.004) | 0.002 (0.002) |
Head’s education (illiterate = 1) | − 0.435*** (0.130) | − 0.110* (0.065) | − 0.406*** (0.131) | − 0.112* (0.065) |
Family size (number) | 0.083** (0.040) | 0.065** (0.021) | 0.062 (0.041) | 0.057*** (0.021) |
Male adult (number) | 0.131** (0.063) | − 0.019 (0.031) | 0.134** (0.063) | − 0.022 (0.030) |
Female adult (number) | 0.125** (0.066) | 0.011 (0.034) | 0.119* (0.067) | 0.010 (0.034) |
Own land (ha) | − 0.115 (0.084) | 0.087* (0.047) | − 0.106 (0.085) | 0.092** (0.047) |
Distance to farmers training center (hour) | − 0.087 (0.077) | − 0.070 (0.047) | − 0.079 (0.078) | − 0.067 (0.046) |
Distance to district office (hour) | 0.054 (0.045) | − 0.018 (0.027) | 0.059 (0.045) | − 0.025 (0.027) |
Plot distance (hour) | − 0.427*** (0.154) | − 0.121 (0.088) | − 0.430*** (0.156) | − 0.118 (0.087) |
Mean rainfall rainy season of past 3 years (mm) | − 0.016*** (0.006) | 0.008** (0.004) | − 0.015** (0.006) | 0.009** (0.004) |
Rainfall variability (std dev) of rainy season of past 3 years (mm) | 0.015 (0.031) | − 0.020 (0.013) | 0.013 (0.031) | − 0.024* (0.013) |
Soil quality (medium = 1) | − 0.155 (0.154) | 0.061 (0.083) | − 0.135 (0.155) | 0.064 (0.082) |
Soil quality (good = 1) | 0.047 (0.158) | − 0.011 (0.085) | 0.089 (0.160) | 0.033 (0.086) |
Crop type (leguminous = 1) | − 0.059 (0.143) | 0.097 (0.074) | − 0.106 (0.144) | 0.068 (0.074) |
Crop type (vegetables = 1) | − 0.692*** (0.215) | − 0.097 (0.137) | − 0.728*** (0.217) | − 0.115 (0.137) |
Soil type (Walka, Vertisol = 1) | − 0.455** (0.231) | 0.155 (0.115) | − 0.431** (0.235) | 0.177 (0.115) |
Soil type (Hutsa, Leptosol = 1) | − 0.202 (0.246) | 0.179 (0.115) | − 0.183 (0.249) | 0.195* (0.115) |
Soil type (Mekayhi, Luvisol = 1) | − 0.690*** (0.254) | 0.118 (0.127) | − 0.659** (0.258) | 0.130 (0.126) |
Soil depth (deep = 1) | 0.102 (0.152) | 0.208*** (0.076) | 0.134 (0.154) | 0.222*** (0.077) |
Soil depth (Steep = 1) | − 0.018 (0.184) | 0.117 (0.101) | − 0.036 (0.187) | 0.099 (0.100) |
Oxen owned (number) | 0.109* (0.061) | 0.097*** (0.033) | ||
Access to irrigation (yes = 1) | − 0.019 (0.137) | 0.095 (0.073) | ||
Access to information (yes = 1) | 0.232 (0.149) | − 0.039 (0.073) | ||
District fixed effect | Yes | Yes | Yes | Yes |
_cons | 1.927** (0.839) | 3.274 (0.456) | 1.693** (0.849) | 3.132*** (0.453) |
sigma cons | 0.655*** (0.022) | 0.647*** (0.022) | ||
AIC | 1597.589 | 1592.517 | ||
BIC | 1886.147 | 1907.711 | ||
Wald Chi2 | 135.12 | 138.08 | ||
Prob > Chi2 | 0.0000 | 0.0000 | ||
Log-likelihood ratio | − 731.73 | − 725.25 | ||
Total observation | 626 | 440 | 626 | 440 |