Macronutrient in soils and wheat from long-term agroexperiments reflects variations in residue and fertilizer inputs

Abstract

Previous studies in the long-term experiments at Pendleton, OR (USA), were focused on organic matter cycling, but the consequences of land management for nutrient status over time have received little attention. Soil and wheat (Triticum aestivum L.) tissue samples were analyzed to determine the macronutrient dynamics associated with residue management methods and fertilizer rate under a dryland winter wheat-fallow rotation. The treatments included: no burn residue incorporation with farmyard manure (FYM) or pea vines, no burn or spring burn with application of N fertilizer (0, 45, and 90 kg ha −1), and fall burn wheat residue incorporation. The results revealed no differences on the effect of residue burning on macronutrient concentration over time. After receiving the same treatments for 84 years, the concentrations of soil organic C, total N and S, and extractable Mg, K, P in the 0-10 cm depth significantly increased in FYM plots compared to the rest of the plots. The N fertilization rate of 90 kg ha −1 reduced the accumulations of P, K, and Ca in grain compared to the 0 and 45 kg N ha −1 applications. The results indicate that residue incorporation with FYM can play vital role in reducing the macronutrient decline over time. Crop yields are no longer increasing at the rate of a couple of decades ago 1 and, simultaneously, the proportion of arable lands are also constantly shrinking 2-a condition that demands increased cultivation under dryland cropping systems. Therefore, examining various soil management practices and their impacts on soil quality, such as macronutrient status, of such regions may contribute to sustainable food production for the next 100 years. Despite the important roles of macronutrients for plant growth, few studies have evaluated their dynamics under dryland cropping systems over extended periods of time. The drylands of the Pacific Northwest (PNW) receive an average annual precipitation of 150-437 mm 3 , while winter wheat requires 500-580 mm of water to complete its lifecycle 4 , and hence, annual dryland wheat production may not be successful in this region. To overcome this water limitation, farmers in this production region of more than two million hectares have opted to utilize a winter wheat-14 months fallow (WW-F) rotation for over 100 years. This system has so far been proven to be economical and stable 5. In the WW-F cropping system, wheat is grown for ten months and the land is in fallow for 14 months to conserve winter precipitation for next year's wheat 6,7. However, during these 14 months of fallow, the surface is exposed to general degradation, wind erosion, and accelerated C and N losses 6. Nevertheless, the WW-F cropping system has proven to be the best solution to sustain wheat production in these regions 7 , therefore, management strategies that can maintain or enhance long-term soil productivity are crucial for this region. Wheat residue burning was a common soil management method during the 1930's in the WW-F cropping system 6 , and is still being practiced by some f...

Agronomic and genetic assessment of organic wheat performance in England: a field-scale cultivar evaluation with a network of farms

“…Both management factors, analysed separately to avoid a non-homoscedastic additive model, also affected grain protein content (Table 5). Higher grain protein content and grain N harvest were recorded on crops where organic fertilisation was applied than on crops where it was not, in line with findings by Shiwakoti et al (2020) and Olesen et al (2009), although these latter authors also found a significant yield increase with the use of manure in organic wheat. Pedersen et al (2012) also found that farmyard manure is a significant source of N in organic wheat but its effect interacts with soil properties and past management.…”

Perennial forages influence mineral and protein concentrations in annual wheat cropping systems

“…Under different fertilizer and tillage treatments, Shiwakoti et al (2019a) found no differences in wheat grain mineral concentration except for manganese (Mn), which increased linearly with nitrogen (N) fertilizer rates. A different yet similar study demonstrated positive correlations between wheat grain Mn concentration and N fertilization, and greater N and Zn concentrations in wheat grain when fertilized with either farmyard manure or inorganic N (Shiwakoti et al, 2019b;Shiwakoti et al, 2020). Shiwakoti et al (2020) also reported an increase in N and S concentrations in wheat grain over time, speculating this could be due to greater N concentration in wheat grain occurring in cases where less rainfall occurred during the growing season.…”

“…(2019a) found no differences in wheat grain mineral concentration except for manganese (Mn), which increased linearly with nitrogen (N) fertilizer rates. A different yet similar study demonstrated positive correlations between wheat grain Mn concentration and N fertilization, and greater N and Zn concentrations in wheat grain when fertilized with either farmyard manure or inorganic N (Shiwakoti et al., 2019b; Shiwakoti et al., 2020). Shiwakoti et al.…”

“…Shiwakoti et al. (2020) also reported an increase in N and S concentrations in wheat grain over time, speculating this could be due to greater N concentration in wheat grain occurring in cases where less rainfall occurred during the growing season.…”

Nutritive and non‐nutritive effects of compost on organic dryland wheat in Utah

“…Active C, as the substrate for microbial activity, is associated with a range of soil health benefits including nutrient cycling, production of organic binding agents, and aggregate formation and stability (Bronick & Lal, 2005;Haynes & Beare, 1996;Tejada & Gonzalez, 2003;Tisdall & Oades, 1982). Cox et al (2001), Reeve et al (2012), Tautges et al (2016), Calderón et al (2018), and Shiwakoti et al (2020 also showed benefits of compost/manure application to a range of dryland soil properties including soil organic C, macronutrients, and enzyme activities. These findings are also consistent with research conducted in more humid regions (Flieβbach & Mäder, 2000;Peacock et al, 2001).…”