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Drought imposes a significant challenge for crop production. However, little is known about the impact of drought priming and nitrogen (N) application and their interactive effects on drought resilience, yield, and grain quality in wheat. Spring wheat (cv. Stettler) was grown in plastic pots (25 cm diameter) with high, moderate, and low soil water levels and received N (added N) or without N (no N added), and subjected to acute drought for 10 days, then rewatering at the tillering stage. Canopy temperature, maximum efficiency of photosystem II, and normalized difference vegetation index were measured at 3-day intervals during drought-recovery periods to quantify drought resistance and resilience. Above-ground dry matter, straw dry matter, seed dry matter, harvest index, and grain N, phosphorus (P), and zinc (Zn) concentrations were determined. Both moderate- and low-water-grown plants had higher drought resistance than high-water-grown plants. The addition of N alleviated acute drought stress in high- and moderate-water-grown plants but exacerbated drought stress in low-water-grown plants. Both high and moderate water resulted in higher grain yields, but had a lower harvest index than low water. The highest and lowest grain N were observed in the low- and high-water-grown plants, respectively. The addition of N increased N and N:P in grains but decreased grain Zn:N. This study showed that moderate drought priming along with N application can improve drought resistance, yield, and grain quality. The results also indicated that canopy thermal imaging is a useful tool for high-throughput quantification of the drought resistance of wheat. [ABSTRACT FROM AUTHOR]

Particulate organic matter (POM) is a labile fraction of soil organic matter (SOM) that can contribute to nitrogen (N) mineralization. We added native and non-native POM to soils with contrasting properties and assessed net N mineralization during a 28 days incubation study. Soils (0–15 cm depth) for this study were a clay soil with a 3-year history of corn ( Zea mays L.), a loam soil with a 2-year history of alfalfa ( Medicago sativa L.) and sandy–loam and silty–clay–loam soils that were cropped in the previous 5 years with a corn-soybean ( Glycine max L.) — corn–forage–forage [45% alfalfa + 55% timothy ( Phleum pratense L.)] and corn–soybean–forage–forage–forage rotation, respectively. The POM was separated by size fractionation (> 53 μm) from coarsely sieved (> 6 mm) soil. The N concentration in POM followed the order loam > silty–clay–loam > clay > sandy–loam, whereas the acid unhydrolyzable fraction, a proxy for the lignin concentration, was the reverse. Compared to soil only, addition of N-rich POM from the loam soil increased net N mineralization in the clay soil and gave similar net N mineralization in the other soils, while addition of N-poor POM from the sandy–loam soil resulted in lower net N mineralization in the loam and silty–clay–loam soils. Multiple stepwise regression analysis showed that net N mineralized due to POM addition was related to the N concentration in the POM (partial R 2 = 0.54) and the initial soil mineral N concentration (partial R 2 = 0.33), suggesting that N mineralized from POM was related more to POM chemical composition than soil properties. We propose that information on POM chemistry in conjunction with soil mineral N concentration and texture could be useful for constructing N mineralization prediction models to improve N fertilizer management in agricultural soils. [ABSTRACT FROM AUTHOR]