Seasonal Dynamics of N, P, and K in an Organic and Inorganic Fertilized Willow Biomass System

Abstract

The seasonal variations in soil nutrient supply and bioavailability were assessed in a willow biomass crop (Salix miyabeana, SX64) treated with 150 and 200 kg available N ha−1of commercial fertilizer (CF), biosolid compost (BC), dairy manure (DM), and control (CT0) at Delhi, NY. Plant root simulator probes were used to measure nutrient supply (inside) and bioavailability (outside) of root exclusion cylinders. Measurements were made in September 2008 and May, August, and October of 2009. Soil moisture content (θd)and foliar nutrient concentrations were also determined. The BC treatments increased soil P supply more than CF and CT0. The supply ofNH4+and K in the soil increased in August but their bioavailability increased in May and October. SoilNO3-and P supply and bioavailability were both high in May. Foliar N and K concentrations were significantly high in May and low in August which could be due to dilution effect caused by increased soil moisture foliar dry weight. Foliar P concentrations increased in September and October. The observed higher soilNO3-mineralization and plant uptake in May suggest that in high soilNO3-conditions willow biomass crops can level and minimize leaching out of the root zone into groundwater.

A Field Bioassay of Nitrogen and Phosphorus Phytoextraction from Biosolids in a Seasonally Frozen End‐of‐Life Municipal Lagoon Vegetated with Cattail

“…The decomposition of organic matter in anaerobic flooded conditions is achieved by a relatively restricted anaerobe population that operates at a lower energy level and is less efficient than in aerated terrestrial systems with a wide range of aerobes (Buresh et al, 2008). Available N (NH 4 + NO 3 –N) supply rate in biosolids in the primary cell of the municipal lagoon that were permanently flooded (∼50 cm) showed that mineralization rates were lower (4.5–5.9 μg cm −2 2 wk −1 ) throughout the growing season (June–September) (Jeke and Zvomuya, 2018b) compared with rates reported for agricultural field soils (200 to >1100 μg cm −2 2 wk −1 ) in Saskatchewan, Canada (Qian and Schoenau, 2005) and biosolids‐amended soils (∼30 to 120 μg cm −2 2 wk −1 ) in Delhi, NY (Quaye et al, 2015). Therefore, N mineralization in our study may be low during spring snowmelt partly due to lower mineralizable N concentration in the biosolids (Jeke et al, 2015b) and/or submerged conditions, which can reduce mineralization rates.…”