Abstract
Sufficient fertility is important for crop growth and yield but supplying a balanced amount of N, P, and K with compost and manure is a challenge and nutrient imbalances can benefit weeds more than crops. The goal of this study was to compare the aboveground growth responses of common northeastern U.S. crops and weeds to addition of composted poultry manure (CPM). A secondary goal was to test whether the observed growth responses to CPM could be attributed to the three macronutrients—N, P, and K—supplied in the CPM. Two field experiments were conducted over 2 yr. Species grown were corn, lettuce, kale, Powell amaranth, common lambsquarters, giant foxtail, and velvetleaf. Plants were grown in soil amended with CPM or single-nutrient organic N, P, and K fertility amendments. Single-nutrient P treatments with bone char did not adequately mimic P supply from CPM. In both years, biomass of all weeds studied increased with CPM amendment rate. Powell amaranth was the most responsive to CPM addition, increasing 1,775 and 159% from the control to the highest CPM rate in 2010 and 2011, respectively. Corn biomass increased by 22% with CPM rate in 2010 but did not increase with CPM rate in 2011. Lettuce biomass increased with CPM amendment rate (175% in 2010 and 109% in 2011), but due to the increased weed biomass at high CPM amendment rates, good weed control will be necessary to maintain this yield benefit. The increase in growth of Powell amaranth, common lambsquarters, and giant foxtail with CPM amendment was not due to N or K, and may have been influenced by P or another factor in the CPM. Velvetleaf was the only species that exhibited increased biomass with N addition (as blood meal), similarly to the increase with added CPM, suggesting the velvetleaf growth response to CPM was due to N in the CPM. The results show that nutrient ratios should be considered when applying organic amendments, because application rates of organic amendments that meet the crop's needs for one nutrient may oversupply other nutrients. Overfertilization will not benefit crop yield, but the results of this study show that high organic fertility application rates are likely to increase weed growth.
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Claims 13
Claim · model-written summary
Weed biomass increased with CPM amendment rate in both years.
Not reportedComparator
Verbatim
e0“In both years, biomass of all weeds studied increased with CPM amendment rate.”
Claim · model-written summary
Powell amaranth biomass rose 1,775% at the highest CPM rate in 2010.
Verbatim
e0“Powell amaranth was the most responsive to CPM addition, increasing 1,775 and 159% from the control to the highest CPM rate in 2010 and 2011, respectively.”
Claim · model-written summary
Powell amaranth biomass rose 159% at the highest CPM rate in 2011.
Verbatim
e0“Powell amaranth was the most responsive to CPM addition, increasing 1,775 and 159% from the control to the highest CPM rate in 2010 and 2011, respectively.”
Claim · model-written summary
Corn biomass rose 22% with CPM rate in 2010.
- Taxon
- Corn
Zea mays subsp. mayse0 - Treatment
- CPM ratee0
- Outcome
- Corn biomasse0
- Direction
- increasede0
- Value
- 22%e0
- Qualifier
- 2010e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Corn biomass increased by 22% with CPM rate in 2010”
Claim · model-written summary
Corn biomass did not increase with CPM rate in 2011.
- Taxon
- CornZea mays subsp. mayse0
- Treatment
- CPM ratee0
- Outcome
- Corn biomasse0
- Direction
- did not increasee0
- Qualifier
- 2011e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Corn biomass increased by 22% with CPM rate in 2010 but did not increase with CPM rate in 2011.”
Claim · model-written summary
Lettuce biomass increased 175% with CPM rate in 2010.
- Taxon
- Lettuce
Lactuca sativae0 - Treatment
- CPM amendment ratee0
- Outcome
- Lettuce biomasse0
- Direction
- increasede0
- Value
- 175%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lettuce biomass increased with CPM amendment rate (175% in 2010 and 109% in 2011)”
Claim · model-written summary
Lettuce biomass increased 109% with CPM rate in 2011.
- Taxon
- LettuceLactuca sativae0
- Treatment
- CPM amendment ratee0
- Outcome
- Lettuce biomasse0
- Direction
- increasede0
- Value
- 109%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Lettuce biomass increased with CPM amendment rate (175% in 2010 and 109% in 2011)”
Claim · model-written summary
Powell amaranth growth under CPM was not attributable to N or K.
Verbatim
e0“The increase in growth of Powell amaranth, common lambsquarters, and giant foxtail with CPM amendment was not due to N or K, and may have been influenced by P or another factor in the CPM.”
Claim · model-written summary
Common lambsquarters growth under CPM was not attributable to N or K.
- Taxon
- common lambsquarters
Chenopodium albume0 - Treatment
- CPM amendmente0
- Outcome
- increase in growthe0
- Qualifier
- not due to N or Ke0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The increase in growth of Powell amaranth, common lambsquarters, and giant foxtail with CPM amendment was not due to N or K, and may have been influenced by P or another factor in the CPM.”
Claim · model-written summary
Giant foxtail growth under CPM was not attributable to N or K.
Verbatim
e0“The increase in growth of Powell amaranth, common lambsquarters, and giant foxtail with CPM amendment was not due to N or K, and may have been influenced by P or another factor in the CPM.”
Claim · model-written summary
Velvetleaf biomass increased with blood meal N, similarly to CPM.
- Taxon
- Velvetleaf
Abutilon theophrastie0 - Treatment
- N addition (as blood meal)e0
- Outcome
- biomasse0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Velvetleaf was the only species that exhibited increased biomass with N addition (as blood meal), similarly to the increase with added CPM”
Claim · model-written summary
N in CPM was suggested to explain the velvetleaf growth response.
- Taxon
- velvetleafAbutilon theophrastie0
- Treatment
- CPMe0
- Compound
- Ne0
- Outcome
- growth responsee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“suggesting the velvetleaf growth response to CPM was due to N in the CPM.”
Claim · model-written summary
The authors recommend considering nutrient ratios when applying organic amendments.
Verbatim
e0“nutrient ratios should be considered when applying organic amendments”
e1“the crop's needs for one nutrient”
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Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.