Climate and landscape mediate patterns of low lentil productivity in Nepal

range from 3rd week of October to end of November, hence the dates bracketed the plausible seeding window for lentil in the rice-based production systems of the Terai. Results Characterization of lentil production across environmental gradients in western Nepal Average rainfall during the lentil growing season (October to March) was 253 mm and daily average temperature was 18.5˚C (Table 1). Seasonal rainfall in the studied year was Table 1. Lentil production characteristics and summary statistics. Variables Variables description Farms without crop failure (N = 665) Full samples (N = 793) Mean Std. Dev Mean Std. Dev Output† Total lentil grains produced (kg) 89.72 165.55 75.24 155.14 Cultivated land† Total cultivated land (ha) 0.70 0.72 Land† Area under lentil production (ha) 0.26 0.31 0.27 0.32 Capital inputs† Total non-labor capital inputs (NRs) excluding seed and fertilizers 1489.32 2930.78 1568.49 2949.26 Household size Number of household members (No.) 7.16 4.01 Gender Dummy, = 1 if household decision maker is male otherwise 0 0.80 Farming experience (years) Years of lentil farming (years) 11.95 12.6 Labor† Total hired and family labor used for lentil production (labor-hours) 101.79 118.54 104.35 117.64 Labor availability Dummy, = 1 if labor is easily available 0.65 Wage rate† On farm wage rate; NRs/day (sub-district level indicator) 306.47 39.21 Lentil specialized farms Dummy, = 1 if farms cultivate lentil on � 50% of their cultivated land 0.38 Input variables Seed† Seed quantity (kg) 11.38 13.72 11.36 13.35

Nitrogen† (N�) Total amount of Nitrogen applied (kg) 0.84 3.27 1.42 4.26 Phosphorus† (P2O5�) Total amount of Phosphorus applied (kg) 1.64 5.6 2.23 6.03 Potassium† (K2O�) Total amount of Potash applied (kg) 0.17 1.68 0.22 1.72 Variety Dummy, = 1 if farms used improved varieties for lentil production otherwise 0 0.08 0.09 Rainfall† Total amount of rainfall during lentil production period October to March (mm), sub-district level 252.89 116.77 253.38 108.76 Waterlogging Dummy, = 1 if lentil growing fields are waterlogged after rainfall otherwise 0 0.27 0.29 Temperature† Average temperature during lentil production (October to March) period (˚C), sub-district level 18.51 1.86 18.6 1.73 Relay seeding Dummy, = 1 if lentil is relay cropped with rice otherwise 0 0.07 0.09 Mixed cropping Dummy, = 1 if lentil is mixed cropped with other crops otherwise 0 0.55 0.57 Tillage method Dummy, = 1 if lentil growing plots are tilled using tractors and/or power tillers otherwise 0 0.35 0.36 Diseases Dummy, = 1 if lentil crop suffered from diseases and/or pest infestation otherwise 0 0.78 0.76 Soil type (sand) Dummy, = 1 if soil is coarse texture otherwise 0 0.20 0.19 Soil type (silt) Dummy, = 1 if soil is medium texture otherwise 0 0.42 0.43 Soil (clay) Dummy, = 1 if soil is fine texture otherwise 0 0.37 0.39 Land type (lowland) Dummy, = 1 if production ecologies lies in lowland otherwise 0 if it is upland 0.60 0.65 Rainfall × lowland Total amount of rainfall (mm) if the production ecology is lowland 131.66 132.39 146.36 131.91

†Variables used in logged form in the production efficiency and technical efficiency analysis. �Urea, DAP and Potash are the fertilizers for the N, P2O5, and K2O used in the model. 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.t001 PLOS ONE Climate and landscape mediate low lentil productivity PLOS ONE | https://doi.org/10.1371/journal.pone.0231377 April 16, 2020 7 / 19