Changes in soil chemical properties and crop yields with long-term cropping system and nitrogen fertilization

Authors: Sainju, Upendra; ALASINRIN, SIKIRU - University Of Ilorin

Submitted to: Agrosystems, Geosciences & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/6/2020
Publication Date: 4/6/2020
Publication URL: https://handle.nal.usda.gov/10113/6937393
Citation: Sainju, U.M., Alasinrin, S.Y. 2020. Changes in soil chemical properties and crop yields with long-term cropping system and nitrogen fertilization. Agrosystems, Geosciences & Environment. 3(1):e20019. http://doi.org/10.1002/agg2.20019.
DOI: https://doi.org/10.1002/agg2.20019

Interpretive Summary: Novel management practices, such as no-tillage, crop rotation, and optimum nitrogen fertilization can enhance dryland crop yields, but information on their long-term impact on soil chemical properties compared to traditional practices is limited. Researchers at ARS, Sidney, MT in collaboration with University of Illorin, Nigeria reported that no-till continuous spring wheat reduced soil pH compared to no-till spring-pea rotation but increased soil organic matter and Olsen-phosphorus concentrations compared to conventional till spring wheat-fallow at the surface soil after 13 years in the northern Great Plains. Increased nitrogen rate reduced soil pH, cation exchange capacity, and Olsen-P, potassium, calcium, and magnesium in the surface and subsurface soils. Annualized crop yields were greater with no-till continuous spring wheat and no-till spring wheat-pea than conventional till spring wheat-fallow. To reduce soil acidity caused by nitrogen fertilization, enhance nutrient availability, and sustain crop yields, producers can benefit by adopting no-till legume-nonlegume crop rotation with reduced nitrogen rate. This practice can reduce nitrogen fertilization rates to nonlegume crops by supplying nitrogen from legume crop residues and lack of nitrogen fertilization to legume crops.

Technical Abstract: Information is needed on the long-term impact of cropping system and N fertilization on dryland soil health and crop yields. We studied the 13-yr effect of cropping systems and N fertilization rate on soil pH, organic matter, electrical conductivity (EC), concentrations of Olsen-P, K, Ca, Mg, and Na, cation exchange capacity (CEC), and base saturation at the 0- to 60- cm depth, and related them to annualized crop yield in the northern Great Plains. Cropping systems were conventional tillage barley/spring wheat-fallow (CTB/WF), no-tillage barley/spring wheat-fallow (NTB/WF), no-tillage barley/spring wheat-pea (NTB/WP), and no-tillage continuous barley/spring wheat (NTCB/W). Nitrogen fertilization rates were 0, 40, 80, and 120 kg N ha-1 to barley planted from 2006 to 2011 and 0, 50, 100, and 150 kg N ha-1 to spring wheat planted from 2012 to 2018. At 0-5 cm, soil pH and CEC were greater with NTB/WP than NTCB/W and CTB/WF and soil organic matter (SOM) and Olsen-P were greater with NTCB/W than CTB/WF. Increased N rate reduced soil pH, Olsen-P, K, Ca, Mg, and CEC at most soil depths. Annualized crop yield was greater with NTCB/W and NTB/WP than NTB/WF and CTB/WF and maximized at 80-100 kg N ha-1. Most soil chemical properties induced by N fertilization were negatively, but Olsen-P, K, and Mg concentrations induced by cropping system were positively correlated with annualized crop yield. No-till barley/spring wheat-pea rotation with 80-100 kg N ha-1 can sustain dryland soil chemical properties and barley and spring wheat yields in the northern Great Plains.