Peanut Digging Losses Across Soil Moisture Contents

Abstract. Soil moisture plays a dynamic role in digger related yield losses. Two years of peanut yield loss data were analyzed for two different fields with sandy coastal plains soils in Blackville, SC. In both fields the sand content throughout was greater than 80%. Both fields were divided into three soil texture zones using soil electro-conductivity (EC) mapping. Similar soil texture properties were demonstrated for each EC zone, across fields. For the 2013 and 2014 studies, respectively: the average sand contents were 95% and 96% for the low EC zones, 93% and 92% for the medium EC zones, and 92% and 88% for the high EC zones; and the average silt contents were 3% and 2% for the low EC zones, 5% and 6% for the medium EC zones, and 6% and 8% for the high EC zones. For each soil texture zone, digging losses were measured for a prescribed top link setting to represent minimum digging losses. Digging losses were also measured for application of the prescribed setting for the high EC zone in all EC zones to represent typical grower settings. Digging for the 2013 study was conducted in dry field conditions with average soil volumetric moisture content of 1.9% and ranging from 0.0% to 3.5%. At prescribed top link positions in 2013, digging losses (dry basis) were 379 kg ha^-1 (338 lb ac^-1) in the low EC zone, 580 kg ha^-1 (518 lb ac^-1) in the medium EC zone, and 673 kg ha^-1 (601 lb ac^-1) in the high EC zone. Digging for the 2014 study was conducted under wetter field conditions with average soil volumetric moisture content of 4.9% and ranging from 0.3% to 7.7%. At prescribed top link positions in 2014, digging yield losses (dry basis) were 88 kg ha^-1 (79 lb ac^-1) in the low EC zone, 442 kg ha^-1 (395 lb ac^-1) in the medium EC zone, and 326 kg ha^-1 (291 lb ac^-1) in the high EC zone. Although direct comparisons are not absolute because two separate fields were used, the results suggest that soils with higher volumetric moisture content at the time of digging result in reduced digging yield losses and reduced need for top link adjustment. This could indicate more profit to be made in peanut production by applying water prior to digging.