Corn and Soil Response to a Recently Developed Pelletized Papermill Biosolids

Abstract

Beneficial utilization of industrial byproducts such as papermill biosolids (PB) provides a unique opportunity to reduce the overall production cost and increase environmental sustainability. Pelletization of a byproduct enhances its marketability by improving the transportation and application. This greenhouse study was conducted to gain a better understanding of the properties and effects of, a recently developed pelletized papermill biosolids (PPB), on corn (Zea mays L.) and soil. Urea and PPB were each applied at four total N rates equivalent to 45, 90, 135, and 180 kg⋅ha−1 and an additional control treatments of 0 was also included. The PPB contained 379 and 14 g⋅kg−1 total N and C and its C:N ratio was 27. Nitrogen treatment significantly (P ⋅plant−1 where application of 180 kg⋅ha−1 of PPB-N produced the smallest plant biomass. Numerically the dry biomass of corn that did not receive any N, corn fertilized with any PPB, and corn fertilized with any urea was 38.3, 26.9 - 41.1 and 38.1 - 40.92 g⋅plant−1 respectively. Nitrogen concentration in corn plants ranged 6.2 - 11.5 g⋅kg−1. Nitrogen concentration in corn that did not receive any urea or corn that received urea was 8.7 - 11.5 g⋅kg−1 and was significantly more than corn treated with any PPB. Total N uptake (removed from soil) by the corn plant was 166 - 455 mg⋅plant−1. Total N uptake by corn that did not receive any N, corn fertilized with any PPB, and corn fertilized with any urea were 327, 166 - 278, and 379 - 455 mg⋅plant−1 respectively. The data suggest that the high C/N ratio (27.2) of PPB resulted in immobilization of PPB-N. Thus the next step will be to research the optimal rates of inorganic N that should be incorporated into this PPB to reduce its C:N to make it an effective high organic matter content N fertilizer. Nitrogen treatment significantly (P g⋅kg−1. The SOM of the treatments fertilized with 90 and 180 kg⋅ha−1 of PPB-N was 19.4 - 19.7 g⋅kg−1 and was significantly higher than soil that did not receive any N. The application of PPB significantly increased the soil total C which was 36.0 and 23.6 g⋅kg−1 in the soil amended with 180 kg⋅ha−1 of PPB-N and the control respectively. The observed increase in SOM and total C in PPB treated soil points to the potential soil health and C sequestration benefits of PPB provided that its C/N ratio can be increased by incorporating inorganic N into it.