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ARS Home » Southeast Area » Florence, South Carolina » Coastal Plain Soil, Water and Plant Conservation Research » Research » Publications at this Location » Publication #303247

Title: Increasing biomass of winter wheat using sorghum biochars

Author
item Sigua, Gilbert
item Stone, Kenneth - Ken
item HUNT, PATRICK - Retired ARS Employee
item CANTRELL, KERI - Former ARS Employee
item Novak, Jeffrey

Submitted to: Agronomy for Sustainable Development
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/9/2014
Publication Date: 11/28/2014
Citation: Sigua, G.C., Stone, K.C., Hunt, P.G., Cantrell, K.B., Novak, J.M. 2014. Increasing biomass of winter wheat using sorghum biochars. Agronomy for Sustainable Development. 35:739-748.

Interpretive Summary: The fertility of highly weathered Ultisols in the southeastern Coastal Plain region of United States is low. In this region, intensive crop production depletes soil nutrients and reduces soil organic carbon (C). Application of crop residues in agricultural systems is an important factor in the control of soil fertility and nutrient cycling. Other agronomic interventions would include addition of C sequestering minerals and pyrolyzed organic residues to soils. Pyrolysis of crop biomass generates a by-product called “biochar”, which can be recycled to sustain nutrient and C concentrations in biomass production fields. We investigated the effects of sorghum (Sorghum bicolor, L) residues (SR) and sorghum biochars (SB) with or without supplemental inorganic phosphorus (P) on biomass and nutrient uptake of winter wheat (Triticum aestivum, L) grown in two Coastal Plains Ultisols (Norfolk and Dunbar soils). The rates for SR and SB were 13,000 and 5,200 kilogram (kg)/hectare (ha), respectively. Inorganic P was added at the rate of 40 kg P/ha. Our results fully support our hypothesis that sorghum biochars would deliver more positive effect on the biomass of winter wheat than the sorghum residues. In highly weathered Coastal Plains Ultisols, addition of pyrolyzed sorghum biochar has provided agronomic benefits and has no negative consequences in terms of wheat growth and uptake. Results have shown that addition of sorghum biochars increased total biomass of winter wheat by about 31% over the control plants. This may seem to indicate that the conversion of sorghum residue into sorghum biochar is a better strategy for both environmental and crop productivity improvement. We may need to consider that we have insufficient evidences to show that sorghum biochars has a better performance than the original sorghum residues. Nevertheless, the contrasting effects of uncharred and sorghum biochars as reported in our study could be important in terms of satisfying the long term environmental risk assessment and better understanding for the use of uncharred and pyrolyzed crop residues in agriculture.

Technical Abstract: The fertility of highly weathered Ultisols in the southeastern Coastal Plain region of United States is low. In this region, intensive crop production depletes soil nutrients and reduces soil organic carbon (C). Application of crop residues in agricultural systems is an important factor in the control of soil fertility and nutrient cycling. Other agronomic interventions would include addition of C sequestering minerals and pyrolyzed organic residues to soils. Pyrolysis of crop biomass generates a by-product called “biochar”, which can be recycled to sustain nutrient and C concentrations in biomass production fields. We investigated the effects of sorghum (Sorghum bicolor, L) residues (SR) and sorghum biochars (SB) with or without supplemental inorganic phosphorus (P) on biomass and nutrient uptake of winter wheat (Triticum aestivum, L) grown in two Coastal Plains Ultisols (Norfolk and Dunbar soils). The rates for SR and SB were 13,000 and 5,200 kilogram (kg)/hectare (ha), respectively. Inorganic P was added at the rate of 40 kg P/ha. Our results fully support our hypothesis that sorghum biochars would deliver more positive effect on the biomass of winter wheat than the sorghum residues. In highly weathered Coastal Plains Ultisols, addition of pyrolyzed sorghum biochar has provided agronomic benefits and has no negative consequences in terms of wheat growth and uptake. Results have shown that addition of sorghum biochars increased total biomass of winter wheat by about 31% over the control plants. This may seem to indicate that the conversion of sorghum residue into sorghum biochar is a better strategy for both environmental and crop productivity improvement. We may need to consider that we have insufficient evidences to show that sorghum biochars has a better performance than the original sorghum residues. Nevertheless, the contrasting effects of uncharred and sorghum biochars as reported in our study could be important in terms of satisfying the long term environmental risk assessment and better understanding for the use of uncharred and pyrolyzed crop residues in agriculture.