1. Dep. of Agronomy Kansas State Univ. 4500 E. Mary St. Garden City KS 67846 USA
2. Former graduate student Univ. of Idaho Moscow ID 83844‐2340 USA
3. Dep. of Soil and Water Systems Univ. of Idaho PO Box 442340 Moscow ID 83844‐2340 USA
4. Retired Univ. of Idaho Extension Northern District, 6755 Kaniksu St. Bonners Ferry ID 83805 USA
5. Dep. of Agronomy Kansas State Univ. Throckmorton Hall Manhattan KS 66506‐5501 USA