Potential amendments for improving productivity of low carbon semiarid soil

Abstract

Abstract Applying soil amendments with high C content can potentially improve soil properties and increase crop yields. The objective of this 3‐yr field study was to evaluate the effects of organic amendments on soil organic C (SOC), chemical properties, crop nutrient uptake, and crop yields in a low C sandy loam soil near Scottsbluff, NE. The field was planted to dry bean (Phaseolus vulgaris L.) in 2017, maize (Zea mays L.) in 2018, and sugar beet (Beta vulgaris L.) in 2019. Char at 22.3, 44.6, 66.9, 89.2, and 133.8 Mg ha–1; biochar at 5.6 and 11.2 Mg ha–1; and composted manure and municipal compost each at 33.6 and 67.2 Mg ha–1 were applied and incorporated into the soil. In 1 yr after application, organic amendments increased SOC level in top 20 cm by 7–60%. In the second year, maize leaf tissue Fe was greater with char treatments and high biochar rate compared with the control. Greater Fe uptake in beet leaf tissue or trend for such was observed in amendment treatments at high rates compared with low rates and the control in the third year. Maize yield was enhanced with char, municipal compost, and high compost manure rate. Biochar was applied at lower rates than other amendments, and it had no effects on the parameters studied. Results suggest that locally available organic products can be potential soil amendments to increase SOC and enhance productivity. Care needs to be taken to prevent salt buildup and unwanted toxic material accumulation associated with amendments.