Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/30/2000
Publication Date: 3/1/2001
Interpretive Summary: The conversion of nonirrigated to irrigated land is a major expense and requires the land owner to make certain economic decions based on crop yield. There is little information available describing the pod kernel quality associated with subsurface drip irrigation (SDI). SDI systems were installed in 1997 and 1998 at two separate locations and on two different soils. The 1997 site was a native grass pasture while the 1998 site followed ywo years of dryland cotton. These systems included two lateral spacings, two emitter spacings, three irrigation water levels, and a nonirrigated (NI) control. Irrigation was applied at 100%, 75% and 50% of estimated crop water use. Average yield data from these two sites show that SDI significantly increased pod yield 38% when compared with NI peanut (3512 lbs/ac). SDI had an 81% pod yield icrease when compared to the Georgia state average (2690 lbs/ac). SDI increased the quantity of jumbo kernels an average of 60% with a maximum increase of 81% over NI. SDI peanut had significantly lower quantity (75% less) of number sized one than NI. These yield data can be used to project the economic feasibility of installing a SDI system.
Technical Abstract: Projected yield data are required to determine the economic feasibility of installing a subsurface drip irrigation (SDI) system. SDI has been successful on a variety of vegetable and row crops, but pod yield and kernel distribution data on peanut (Arachis hypogaea L.) under SDI are limited. Two SDI systems were installed, one in 1997 and the other in 1998. Site 1 (1997) was converted from native grass pasture. Site 2 (1998) was converted from cotton. SDI systems include two lateral spacings (0.91 and 1.83 m apart at 0.3 m soil depth), two emitter spacings (46 and 61 cm), three irrigation water levels, and a nonirrigated (NI) control. Irrigation water was applied daily based on estimated ET where irrigation level one (IL1) was ET*Kc, and IL2 and IL3 were 0.75 and 0.5 times IL1. SDI significantly increased pod yield 38% when compared to NI peanut (3937 kg ha-1; 3512 lbs/ac). SDI showed a 81% pod yield increase over the state average. SDI increased the quantity of jumbo kernels an average of 60% with a maximum increase of 81% over NI. SDI peanut had significantly lower quantity (75% less) of number one peanut kernels than NI. Overall, in the installation year, SDI had higher pod yields and larger kernel size than NI treatments. These yield data can be useful when installing a SDI system.