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

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 system and N fertilization rate on soil chemical properties 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 (Hordeum vulgare L.)/spring wheat (Triticum aestivum L)-fallow (CTB/WF), no-tillage barley/spring wheat-fallow (NTB/WF), notillage barley/spring wheat-pea (Pisum sativum L) (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 to 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, 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 correlated, but Mg concentration at 30-60 cm induced by cropping system was 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. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Relationship between soil carbon and nitrogen, soil properties, and dryland crop yields

“…Phosphorus is a relatively immobile nutrient and can be held by SOC, resulting in reduced availability to crops (Dick & Gregorich, 2004;Johnson, 1991;Kapland & Estos, 1985). It is not surprising to observe positive correlations among SIC, pH, and Ca concentration in Froid, as SIC increases when pH and Ca concentration increase (Sainju & Alasinrin, 2020).…”

“…This was not the case in Sidney where treatments did not differ in SOC, STC, SIC, and STN even after 14 yr of experimentation, resulting in fewer relationships with nutrients. Nitrogen fertilization can reduce the level of some nutrients compared to non-N fertilization (Sainju & Alasinrin, 2020), which may affect the relationship in Sidney compared to Froid where N fertilization treatment was absent. Coarsetextured soil in Froid may be more responsive to management in chemical properties than fine-textured soil in Sidney, resulting in enhanced relationship in Froid (Sainju et al, 2015;Sainju & Alasinrin, 2020).…”

Carbon dioxide flush as a soil health indicator related to soil properties and crop yields

“…The mean monthly air temperature at the site is 8˚C and annual precipitation is 357 mm. The 14-yr-old site in Sidney, MT (48 o 33′ N, 104 o 50′ W) was established in 2006 (Sainju & Alasinrin, 2020), where the soil was a Williams loam (fineloamy, mixed, superactive, frigid, Typic Argiustolls), with sand, silt, and clay concentrations of 350, 325, and 325 g kg −1 respectively, pH of 7.2, and soil organic C of 13.2 g kg −1 at the 0-to-20-cm depth. Mean monthly air temperature at the site is also 8˚C, with an annual precipitation of 340 mm.…”

“…After grain harvest, crop residues were returned to the soil. Further details are shown in Sainju and Alasinrin (2020).…”

“…Negative correlations, however, occurred between 1dC, 4dC, and some micronutrients in Sidney. Nitrogen fertilization has a negative effect on nutrient concentrations compared with no N fertilization (Sainju & Alasinrin, 2020), which also may have 31.6 (± 6.7)…”