| Impact ID | 7957 |
| Impact Type | Competition |
| Study Type | Experimental |
| Study Location | Laboratory |
| Impact Description | Found that the presence of Echinochloa crus-galli (barnyard grass) in tomato fields reduced the concentrations of nitrogen, phosphorus, and potassium in the leaves of tomato plants. |
| Reference | 24890 |
| Cost | |
| Location | Sunderland, Massachusetts, USA |