Climate and landscape mediate patterns of low lentil productivity in Nepal

we consider estimates from production function are more reliable than those from the Tobit model. Parameters estimates for technical efficiency. The parameters for the technical effi- ciency model as specified in Eq (2) are presented in Table 3. In order to correctly interpret the Table 3. Maximum likelihood estimates of the parameters in the stochastic production frontier for lentil production in western Nepal. Variables Stochastic frontier model Tobit model Coefficient Std. error Coefficient Std. error Production frontier Lentil land (ha) 0.798��� 0.075 0.397��� 0.121 Labor (hours) 0.069�� 0.036 0.153�� 0.063 Non-labor capital (NRs.) 0.019�� 0.009 0.060��� 0.016 Seed (kg) 0.147��� 0.057 0.310��� 0.102 Nitrogen (kg) 0.040��� 0.015 -0.111��� 0.025 Phosphorus (kg) -0.018 0.014 -0.021 0.023 Potash (kg) -0.038 0.021 -0.033 0.031 Rainfall (mm) -0.400��� 0.116 -1.571��� 0.204 Waterlogging (1 = yes) -0.183�� 0.089 -0.572��� 0.147 Temperature (˚ C) -1.257��� 0.473 -3.382��� 0.857 Variety (1 = improved) -0.246� 0.132 -0.491�� 0.225 Relay cropping (1 = yes) -0.495��� 0.150 -1.180��� 0.249 Mixed cropped (1 = yes) -0.067 0.090 0.198 0.145 Tillage method (1 = tractors) 0.110 0.095 0.333�� 0.152 Diseases (1 = yes) -0.379��� 0.093 0.182 0.156 Sandy soil† (1 = sandy) 0.085 0.102 0.516��� 0.175 Clay soil (1 = clay) 0.459��� 0.100 0.632��� 0.150 Lowland (1 = lowland) 0.324��� 0.102 -0.013 0.168 Rainfall × lowland -0.221��� 0.024 -0.360��� 0.041 Constant 12.01��� 1.828 20.25��� 3.286 s2 v 0.536��� 0.052

Wald/LR ch2 [19] 701.54 357.03 Log likelihood -916.85 -1414.07 Technical inefficiency Cultivated land (ha) 0.351��� 0.101 Household size (no) -0.005 0.018 Gender of household head (1 = male) 0.017 0.169 Farming experience (years) -0.020��� 0.006 Labor availability (1 = easily available) -0.242� 0.141 Wage rate (NRs) 0.174��� 0.043 Lentil specialized farms (1 = yes) 0.859��� 0.167 Mean technical efficiency (TE) score 0.408 TE in upland (N = 261) 0.431� TE in lowland (N = 404) 0.395 No. of observations 665 793 ��� indicates significant at 1% level, �� indicates significant at 5% level and � indicates significant at 10% level. †The base category is the silt soil. TE stands for technical efficiency. Exchange rate: 1 US $ = NRs 98.6 and NRs. 102.7, respectively, for year 2014 and 2015 [86]. https://doi.org/10.1371/journal.pone.0231377.t003 PLOS ONE Climate and landscape mediate low lentil productivity PLOS ONE | https://doi.org/10.1371/journal.pone.0231377 April 16, 2020 11 / 19