The use of pesticides in agriculture is often seen as a negative aspect in food production. Nevertheless, their use aims to avoid yield and economic losses. The high amount of pesticides used for production in the Netherlands before the 1980’s captured the attention of scientists and policy makers. Several measures were taken to reduce the dependence on pesticides in agricultural production. Still, the effects of pesticide use need to be continuously monitored and evaluated. Using a database with information on crop fields, yield and spraying operations, provided by AgroVision B.V. (Cropmanagement); we evaluated the relation between pesticide use yield, environmental impact and biophysical conditions applying Linear Mixed Models (LMM), Stochastic Frontier Analysis (SFA) and Boundary Line (BL).
Yield was c.a. 8% lower in 2016 compared to 2017 and 2015. Seed potato yield was c.a. 14 ton/ha lower than ware (50.9 ton/ha) and starch potato (49.1 ton/ha). Seed potato showed less pesticide sprayings (13) than ware (16) and starch potato (17); and a lower pesticide input with 10 kg of active ingredient (AI) per hectare compared to ware (11.5 kgAI/ha) and starch (12.7 kgAI/ha). Years 2016 and 2017 presented a higher AI input (12 AI kg/ha) compared to 2015 (10.8 AI kg /ha). Ware and starch potato varieties Hansa and Festien showed the highest AI input compared to Melody (10kgAI/ha) and Seresta (12. kgAI/ha); variety Fontane showed higher AI input (c.a.10kgAI/ha), than Innovator and Spunta (c.a. 9 AI kg/ha) in seed potato. Concerning regions AI input related to N Coast was the lowest (8.7 AI kg/ha), while South accounted for the highest input (14.1AI kg/ha).
The environmental impact points (EIP) were 20% higher in 2016 compared to 2015 and 7% higher compared to 2017. Ware and starch potato accounted for the highest EIP values, (c.a. 3000 EIP); while seed potato showed the lowest (2561 EIP). Soil life is the most affected by pesticide use in the three potato crop types; aquatic life was mostly affected by ware potato production and ground water was mostly affected by starch potato. Fungicides accounted for the highest share in the total AI input; around 70% in seed and ware potato and ~80% in starch potato. Almost a third of the EIP were related to insecticides despite its low contribution to total AI (3%), which shows its high environmental burden.
Fungicides affected yield positively in a small extent, the effect was consistent in all crop types with c.a. 0.07 ton/ha in ware and starch potato, and 0.10 ton/ha in seed potato. A negative influence on yield in 2016 was found significant in ware and starch potato (c.a.-0.10). The effect of the interaction fungicide x insecticides on yield was found positive in starch potato, but negative in seed potato; while the interaction between herbicide x insecticide positively affected yield in ware potato. The interaction between insecticide and sandy soil positively affected yield in ware and starch potato.
Yield plateau showed an AI input of ~ 5kg AI/ ha. Narrow differences were found between AI amount in starch potato for different yield levels. Low yielding fields coincide with low EIP and AI in ware in starch potato. Minimum thresholds of EIP per unit of AI are similar in ware, starch and seed potato from 100-140 EIP. Nevertheless, upper thresholds vary among crop types suggesting that pesticide combinations in ware potato (1300 EIP) have a higher environmental impact than seed (130 EIP) and starch potato (326 EIP). A wide range of EIP values were found for a given AI input level, this suggests that pesticide pollution characteristics play an important role in the environmental impact of the fields.
We concluded that a) yield, AI input, and environmental impact are strongly influenced by the type of potato produced, b) low amounts of AI input does not necessarily imply less environmental impact, c) the relation between AI input and yield is limited and d) the wide range of AI and EIP for a given yield suggest that shift from average yield to high yield could be done without increasing the environmental impact.