Exogenous C and N inputs in the greenhouse tomato production system in Shouguang, northern China (kg ha^-1 season^-1).

1C input from chicken manure and wheat straw; N input from mineral fertilizer, organic manure and irrigation water; 2WS: winter-spring growing season, AW: autumn-winter growing season; 3Since 2006AW chopped wheat straw and dry chicken manure was broadcast as a basal fertilizer and the treatment was labeled as “MN+S” instead of “MN”;