Predicting Soil Temperature Using Air Temperature and Soil, Crop, and Meteorological Parameters for Three Specialty Crops in Southern New Mexico

• Published in: Applied engineering in agriculture Vol. 26; no. 1; pp. 47 - 58
• Main Authors: Sharma, P, Shukla, M.K, Sammis, T.W
• Format: Journal Article
• Language: English
• Published: 2010
• Subjects: air temperature; Allium cepa; Capsicum annuum; Carya illinoinensis; hot peppers; meteorological parameters; nut crops; onions; pecans; planting date; regression analysis; root zone temperature; seedbeds; sensors; simulation models; soil density; soil temperature; vegetable crops; New Mexico
• ISSN: 0883-8542; 1943-7838
• DOI: 10.13031/2013.29474

In southern New Mexico, low temperatures occur during early spring that can affect the germination of crops such as chili ( Capsicum annuum L.) and onion ( Allium cepa L.). Thus, knowledge of soil temperature can be useful to determine the planting date of temperature-sensitive crops. Predicting soil temperature using air temperature, available at most weather stations, and soil and meteorological parameters could be a cost-effective solution. The objective of this research was to develop a semi-empirical model with easily available soil and meteorological input variables to predict soil temperature in the seed beds of chili and onion and the root zone of pecan trees. This study was carried out in eight fields in the Mesilla Valley of New Mexico: five fields of chili during 4 March 2004 to 18 May 2004, two fields of onion during 1 January 2007 to 25 June 2007, and one field of pecan during 1 April 2004 to 26 November 2004. Temperature sensors and data loggers were installed in each field to measure soil temperature every half hour. A Watermark sensor or a TDR waveguide was buried in each field to measure hourly soil water content. The sensitivity analysis showed that soil temperature predictions were most sensitive to the annual amplitude in mean monthly temperature and average annual air temperature and least sensitive to the soil bulk density. The absolute difference between simulated and measured soil temperatures were 2.68 approximately C approximately 1.82 approximately C (Mean approximately STD) for onion, and 1.57 approximately C approximately 1.07 approximately C for chili during spring, and 3.67 approximately C approximately 1.47 approximately C and 1.60 approximately C approximately 1.33 approximately C during summer. A linear regression analysis between the measured and simulated soil temperatures produced a coefficient of determination (R 2 ) ranging from 0.73 to 0.88 for chili, 0.90 to 0.93 for onion, and 0.84 to 0.86 for pecan. The soil temperature model was in good agreement with Campbell finite difference solution (0.87 < R 2 <0.98). Thus, a semi-empirical model based on easily available soil, meteorological and crop parameters was sufficient to predict the soil temperature in the seedbed and can be used to decide planting dates for temperature-sensitive crops such as onion and chili.