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A Crop‐Specific Drought Index for Corn: II. Application in Drought Monitoring and Assessment
Author(s) -
Meyer Steven J.,
Hubbard Kenneth G.,
Wilhite Donald A.
Publication year - 1993
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1993.00021962008500020041x
Subject(s) - crop , growing season , agronomy , zea mays , environmental science , biology
How drought is perceived, and defined, determines the likely response of decision makers to a drought event. Since drought response is usually based on some type of assessment of the severity and duration of the event, a critical element of a drought response strategy lies in the incorporation of objective and reliable impact assessment techniques. However, a long‐standing problem in responding to past droughts has been the lack of reliable techniques for monitoring the drought event and assessing probable impacts. This paper describes a new method to reliably monitor and assess weather's probable impact on corn ( Zea mays L.) yields, on a crop reporting district (CRD) level, any time during the growing season. The 1990 growing season was used to demonstrate the ability of the crop‐specific drought index (CSDI) to monitor and assess the condition of East Central Nebraska's corn crop every 10 days, starting 17 June, until a definitive projected CSDI value became established. A 3‐wk hot and dry spell (24 mm of rainfall during the 3‐wk period 28 June‐17 July) that immediately preceded silking resulted in a 17 July CSDI assessment, based on the climatological record of the CRD, that projected yields to be only 63% of the maximum yield previously attained in this CRD. However, a substantial rainfall event during the week of silking alleviated the stressful conditions, and by the beginning of the early grain fill period (blister stage), a 6 August CSDI assessment projected the final CSDI value to within 3% of the actual CSDI (projected and actual yields were 86 and 83%, respectively, of the maximum yield previously attained in Nebraska's East Central CRD). The results of this study demonstrate that the CSDI can monitor and assess weather's impact on corn yields on a CRD level.