The objective of this study was to evaluate weed control, crop yields, potential soil loss, and net returns to management of an integrated weed management system in no-till corn and soybean compared to an herbicide-based strategy. The integrated weed management system reduced herbicide inputs by delayed cover crop termination, herbicide banding, and high-residue cultivation (reduced herbicide [RH]), while the other system used continuous no-tillage and herbicides to control weeds (standard herbicide [SH]). Research was conducted within the Penn State Sustainable Dairy Cropping Systems Experiment, where corn and soybean are each planted once in a 6-yr crop rotation. In this 3-yr study, weed density and biomass were often greater under RH management, but weed biomass never exceeded 19 g m–2in corn and 21 g m–2in soybean. Corn yield and population did not differ in any year, and net returns to management were $33.65 ha–1higher in RH corn due to lower herbicide costs and slightly, though not significantly, higher yields. Soybean yield was lower in RH compared to SH in 2 of 3 yr, and was correlated with soybean population and cover crop residue. Net financial returns were $43.69 ha–1higher in SH soybean compared to RH. Predicted soil loss never exceeded T (maximum allowable soil loss) for any treatment and slope combination, though soil loss was 100% greater on a 10% slope under RH management (vs. SH) due to cultivation.

Red clover (Trifolium pratense L.) and hairy vetch (Vicia villosa Roth) are leguminous crops ("green manure" hereaft er), widely studied for their N 2 -fi xing contributions to cropping systems. Under certain circumstances they can provide weed control in cash crops. Th is study compared weed control, crop yields, herbicide use, and economic performance of these green manures in a no-till winter cereal-green manure-corn (Zea mays L.) silage cropping sequence in central Pennsylvania. Red clover was interseeded into winter wheat (Triticum aestivum L.) or rye (Secale cereale L.), while hairy vetch and triticale (X Triticosecale) were planted aft er winter cereal harvest. Compared to hairy vetch, red clover provided continuous soil cover between the winter cereal and corn and two herbicide applications could not be applied (one in wheat and one prior to seeding hairy vetch) to the red clover, reducing herbicide active ingredient use by 28%. Weed infestation in wheat and corn did not differ between green manure systems, but corn yield following red clover averaged 3320 kg ha -1 more, and 2012 wheat yield was 180 kg ha -1 greater in the red clover sequence. Corn aft er hairy vetch-triticale had lower corn plant population in 2012-2013. Yield diff erences in corn in 2012 probably resulted from population diff erences. Primarily because of red clover forage value, the red clover system resulted in greater net returns to management by US$1360 ha -1 , and even without the forage harvest, the red clover system would have been more profi core ideas• As a green manure, red clover provided multiple benefi ts over hairy vetch and triticale.• Red clover underseeded in winter grain, produced continuous cover, forage, and higher corn yield.• Compared to hairy vetch and triticale, red clover controlled weeds with less herbicide.• Red clover was more profi table than hairy vetch.