Irrigation and Nitrogen Management Web- Based Tool for Lettuce Production

Transcription

1 Irrigation and Nitrogen Management Web- Based Tool for Lettuce Production Michael Cahn Irrigation and Water Resources Advisor University of California, Cooperative, Monterey Co

2 Acknowledgements Richard Smith, UC Farm Advisor, Monterey County California Department of Food and Agriculture, Fertilizer Research and Education Program UC ANR Communication Services, Bryon Noel Grower participants Chiquita FreshExpress Tanimura and Antle

3 The Central Coast has serious nitrate issues : Salinas Santa Maria

4 Coastal Valleys : Wall-to-wall vegetable crops 2-3 crops per year spinach 6% celery 5% cauliflower 8% broccoli 23% lettuce 58%

5 Ways to improve nitrogen use efficiency : Factor residual soil nitrate into fertilizer calculations Pre-sidedress soil nitrate testing : 20 PPM NO 3 -N threshold enough to carry crop for several weeks

6 Applying PSNT on a field scale : Standard BMP Std: 212 lbs N/Acre BMP: 146 lbs N/Acre lbs N/A Difference 66 lbs N/A Ave Field

7 Ways to improve nitrogen use efficiency : Use evapotranspiration-based irrigation scheduling CIMIS weather network

8 ET-based Irrigation Scheduling Converting Reference ET to Crop ET: ET crop = ET ref K crop K c can vary from 0.1 to 1.2 CIMIS weather network

9 29 DAP 41 DAP 1.0 Estimated Kc of Lettuce sprinkler irrigation events Crop Coefficient (Kc) DAP 0.4 Drip 65 DAP 0.2 Sprinkler Average Kc = 0.33 during germination with sprinklers Days after Planting

10 Applying ET-based scheduling on a field scale : Water savings

11 So why don t growers uniformly adopt these practices? One farm manager may be responsible for >100 fields during a production season Irrigation and fertilizer management must fit with other activities (tillage, pest management, personnel management, equipment constraints) Potential crop value overwhelms fertilizer and irrigation costs

12 Web-based Irrigation and N management software for lettuce

13 CropManage Web-based Tool: Assist growers in making decisions on irrigation and nitrogen fertilizer management Intuitive, simple, quick to use. Accessible from smart phone, tablet computer, desktop computer Guide irrigation schedules using CIMIS weather data. Guide nitrogen fertilization decisions using soil nitrate test data. Maintain and share irrigation, fertilizer, and soil test records for multiple fields and farms.

14 Integrate information from multiple sources Soil and Ranch Crop ET model Watering Recommendation CIMIS ETo Database Driven Web Application N fertilizer Recommendation Soil nitrate test Field sensors Crop N model Display and export water and fertilizer records Decision support using crop models

15 How is N fertilizer rate determined from a soil nitrate test? Recommended Fertilizer N = Future Crop N uptake (residual NO 3 -N - threshold NO 3 -N) Soil N mineralization potential Soil NO 3 -N by quick test or lab analysis

16 How is irrigation requirement determined? Spatial CIMIS ET o Reporting

17 100 Iceberg lettuce canopy cover Canopy Cover (%) Days after Planting

18 Available moisture depends on soil type and rooting depth 0 Rooting Depth of Lettuce Rooting Depth (inches) Days after Planting

19 Interface with UCD SoilWeb Tool

20 Interface with field sensors :

21 Ranch Summary

22 Soil Summary Fertilizer Summary

23 Water Summary Table

24 Field Validation of CropManage Applied water Commercial Treatment sprinkler drip 1 inches Yield lbs/acre Grower Standard CropManage comparison was on last 7 irrigations Treatment Applied N Fertilizer Commercial Yield lbs per acre Grower Standard CropManage

25 The road ahead

26 Final Thoughts Web applications can repackage complex data sets and mathematical models into simple to use decision support tools Web apps can also help growers track their practices and demonstrate they are managing nutrients and water efficiently CropManage is not just for growers. It is a potential tool for crop consultants and advisers to use in assisting growers with water and N management decisions.

27