I am wondering about legumes that can be used to smother weeds. We have used Mucuna successfully but only in open fields. Now wanting to work between young fruit trees and planning on trying Jack Bean but hear mixed reports. Have recently read about Scarlet Runner Bean (Phaseolus coccineus) as a possibility. Do any of you on this list have experience using scarlet Runner to smoother weeds? If so, would appreciate your feedback. It would be nice to grow something that is edible…as well as useful in weed control. Thanks
Mucuna is a great smother crop! But I would agree that isn’t great for intercropping with trees. @Erwin_Kinsey or @Neil_Rowe_Miller would you consider scarlet runner bean a good smother crop? Would it potentially climb trees? Glen is in higher altitudes of Honduras.
Some limited climbing of trees is ok because we can occasionally cut the vines. My main interest is its potential as a smother crop. If it is as good or nearly as good a canavalia and we can eat the Scarlet Runner, that would make it a winner in my view.
See: Restoring the Soil by Roland Bunch:
You can read or listen to this great NCAT’s ATTRA Sustainable Agriculture article (LINK HERE) on using Scarlet Runner as a cover crop. They note they did not see great weed suppression in their test plot, but noted two papers that got weed suppression for maize, artichoke, and sunflower intercropping systems. Of course none of these crops were young fruit trees. NCAT also noted this cover crop may require great irrigation to be successful for weed suppression.
However, there was one paper (LINK HERE) that said they saw improved bulk density with an intercropping system of mango+guava+cow peas.
Guinevere, thanks so much for sharing those links. I am not familiar with NCAT. Is it somewhat similar to ECHO?
I apologize for the delayed response. I am not affiliated with NCAT (National Center for Appropriate Technology) so I can only speak on what I learned from their sight. I believe ECHO and NCAT both strive to reduce global food insecurity, and NCAT has several field offices in the US. Here is a link to NCAT’s home page (LINK HERE), NCAT houses several focus specific programs like ATTRA (Appropriate Technology Transfer for Rural Areas). It is this program that conducted the study I noted above.
I have been using and experimenting with Jack Bean and Lablab. What I suggest is that when you have gotten some good advice here from different sources and from reading Roland Bunch’s book Restoring the Soil then you get a wide variety of perennial spreading legumes and even sources from different places so you are getting a variety of variants of those species and test them out by mixing them together. What dominates from the mix will tell you what you need to plant for that given area and even orchard soils are highly variant so the mix will help you with that as well so you can in the future dial in the right smoother crop with all the different soil types with their associated fertility and waterlogging and droughtiness factors. The literature and people’s advice is helpful but you need to set up your own experiment from a mix and keep adding to the mix as you get more plant material. Beans do not cross much at all so you can collect seed from those that do the best job smothering in combination with those that require the least work removing from climbing the trees. Another thing you might try that I do is to use human urine as fertilizer. Someone above made a great comment on irrigation as a way to increase the smoother crop effect but you may not have that as an option. So fertilizer application may greatly increase growth, particularly those rich in phosphorus and potassium. This is particularly true when a legume if first starting out and has little nodulation and so extra nitrogen and other nutrients are helpful. It is my understanding and others can correct me on this because this is quite technical, a legume can regulate the energy going to nodulation and will grow faster in the presence of more nitrogen which allows the legume to expend less feeding the bacteria with photosynthate because it does not need the help and it is a cost to the plant to provide so much photosynthate. So getting that fertilizer out at the right time following a rain when the salt index is going to have less stress impact is a good idea. Later the fertilizer will have less impact since the plants are already nodulating but the improvement could still be significant since a lot of the phosphorus that the legume takes up is given to the nodule so you will get improved synergistic effects from fertilizer since the legume needs the fertilizer for itself and to assist the bacteria to increase nodulation formation (size and number). And of course, we need to get those legumes established at the beginning of the rainy season for optimal growth. A pigeon pea planted in advance may provide some shade to assist in the establishment of the smoother crop as a “nurse” species but this may interfere with orchard activities if you are moving around equipment. And those of you with more experience please comment and correct me on any of this.