Economics of site-specific weed control

H. Oebel, R. Gerhards, L. Weiershäuser, W. Kühbauch

Introduction

The application of precision weed control techniques in practical agriculture depends on the economic benefit for the farmer. Additional costs for technical equipment for sitespecific herbicide application and weed sampling have to be compensated by herbicide savings. (Gerhards et al. 2005) The TURBO project allowed together with the Kuratorium f�r Technik und Bauwesen in der Landwirtschaft (KTBL) to calculate the costs of sitespecific weed control technologies used on the Hurtz farm (Nideggen-Berg) and the experimentation farm Dikopshof (Wesseling).

savings table
Herbicide savings on the Hurtz farm (1) and the experimentation farm Dikopshof (2) since 2004

Material and Methods

Weed distribution maps were created by manual sampling techniques, using a mobile GPS and digital image analysis techniques.

Additional costs of a multiple sprayer (cost price, additional application time, water) were calculated and compared with a conventional sprayer.

Costs
Costs of different sampling methods and application technologies
Steps for weed sampling using a mobile GPS
Steps for weed sampling using a mobile GPS

Results

Manual weed sampling methods are time consuming and with costs about 60 /ha not relevant for practise. GIS-based weed sampling using an handheld PDA and less sampling points can reduce costs to 26,60 €/ha. Faster and cheaper is the creation of application maps using digital image analysis with 10,92 €/ha (Offline) and 6,75 €/ha (Online).

Additional costs for the application technology was calculated with 5,34 €/ha. Herbicide savings varying on crop and farm specific weed situation. Average savings were 27,30 €/ha.

Conclusions

By using digital image analysis (Offline) to create application maps and the performance of three herbicides using a multiple sprayer the additional costs of 16,26 €/ha are compensated by herbicide savings of 27,30 €/ha.