Using un-composted leaf mulch on trellised lima bean

After recent scorching weather, Rutgers' Joe Heckman checks soil moisture retained under leaf mulch layer compared with adjacent cultivated bare ground. A 5-6" leaf mulch layer (~35,000 lb./A) was placed at transplanting in May.

Lima bean is a legume. We inoculated seeds and transplants and are not expecting leaf mulch decomposition to affect nitrogen fertility of the crop. At harvest, we will check for yield reduction from potential microbial immobilization of soil N (from mineralization of the high carbon soil amendment).

We are seeing reduced weed pressure in leaf-mulched rows. Joe’s previous field research showed that mineralization of the leaves has a positive impact on soil nitrogen fertility the next season. If you would like to visit this lima bean field leaf mulch demonstration, give me a call or email. We can arrange a time when you will be coming through the Rutgers Campus New Brunswick area.

Jack Rabin