Green manures, cover crops and nitrogen fixing trees

[islandguy]

Back on this thread a couple of years on, glad it is still going. Now have 10 rai graded and planted in trees, mostly heirloom flowering trees, and focused on getting them past this nasty drought. Land is good dirt, mostly without any plants at all since it hasn't rained since it was graded. We are still living elsewhere and have a great local professional doing all of this. So after this introduction, my hope is that one or more of you soil building heroes can suggest a ground cover to outcompete the weeds that will be coming. One suggestion is to just mow closely and let local plants that only grow a few inches tall come to predominate. Another way to go would to broadcast some of the bean seeds and other cover crops suggested on this thread and just let them respond to the rains we all hope are coming. I know that that is an awfully simple approach and won't have a high return, but wonder what you think? Thanks for any suggestions, and hope to contribute more in the future. I have a family farming background and used to do lots of organic gardening and some farming, including in Hawaii.

[drtreelove]

10 rai of flowering trees? Awesome. I'd love to see that, and to smell the fragrant ones.

I vote for seeding a legume cover crop. I've used jack beans, black beans and others, free from land dept. But if you don't have an irrigation system, wait to seed until you are sure that rain is happening, otherwise it's a waste. The longer that seeds lay on the ground without water, the more they will deteriorate in viability, not germinate, or get eaten by birds and other critters, or decayed.

I used the pre-existing weed crop to my advantage. As the rains started, I seeded the beans right into the grasses and other existing growth in the orchards. Then with the seeds down against the soil among the weeds, I'd cut existing growth with a krueng tat ya, bladed brush cutter, and leave lay as a mulch on top of the seeds. I'd get good germination due to rain and mulch on top of the seeds. Grow for a couple of months, maximum lush vegetative growth, then cut and leave lay as mulch before the plants get hardened, flower and go to seed.

If your trees are young and spaced far apart, and if you have resources for tractor work, you can disk harrow or rototill the green manure crop into the soil surface for maximum benefit of soil organic matter. But as the trees mature and the absorbing root systems spread and occupy the entire soil volume between trees, it is detrimental to disk or rototill and destroy the surface absorbing roots. Go for no-till orchard management, cut grass and green manure and leave lay as surface mulch.

[islandguy]

Thanks for the suggestions, make a lot of sense. Please mark your calendar for Spring/flowering season of 2018, should be lots to see (fingers crossed), you are most welcome to visit. While we chose some international favorites (Royal poinciana, pua'keni'keni,) emphasis was on the kind of Thai fragrant trees my wife misses from her youth.

Your suggestions go with my preferences also. I am hoping to get into humus building in as big a way as time and easily obtainable local resources allow, but that is as much for fun and to create a demonstration project as any real need. This property was chosen partly because it had good soil instead of bad soil. The cover cropping is always a good soil builder but I am more worried about weeds for the short term. When you say seed (as a verb), what method are you thinking of? Don't think I will have a tractor with a set up to do this (although it might me possible to rent one), and don't want to crawl around for a few weeks with a dibble ?. Is there some better method than just throwing it around by hand? Since there probably won't be any weeds/ground cover at all until a week or two after a rain or three, do you think I should wait before spreading the seed?

Reading this thread, I can take a look to see about inoculating, soaking, and scoring to get the seeds to germinate, but probably will try to get something easier to start. Thanks for any more suggestions!

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10 rai of flowering trees? Awesome. I'd love to see that, and to smell the fragrant ones.

I vote for seeding a legume cover crop. I've used jack beans, black beans and others, free from land dept. But if you don't have an irrigation system, wait to seed until you are sure that rain is happening, otherwise it's a waste. The longer that seeds lay on the ground without water, the more they will deteriorate in viability, not germinate, or get eaten by birds and other critters, or decayed.

I used the pre-existing weed crop to my advantage. As the rains started, I seeded the beans right into the grasses and other existing growth in the orchards. Then with the seeds down against the soil among the weeds, I'd cut existing growth with a krueng tat ya, bladed brush cutter, and leave lay as a mulch on top of the seeds. I'd get good germination due to rain and mulch on top of the seeds. Grow for a couple of months, maximum lush vegetative growth, then cut and leave lay as mulch before the plants get hardened, flower and go to seed.

If your trees are young and spaced far apart, and if you have resources for tractor work, you can disk harrow or rototill the green manure crop into the soil surface for maximum benefit of soil organic matter. But as the trees mature and the absorbing root systems spread and occupy the entire soil volume between trees, it is detrimental to disk or rototill and destroy the surface absorbing roots. Go for no-till orchard management, cut grass and green manure and leave lay as surface mulch.

[drtreelove]

I broadcast seeds (or fertilizer) by hand, out of a bucket. But I've been doing it so long I'm like a human whirlibird spreader and get pretty even distribution. There are spreaders available of various sizes and configurations, from hand held to tractor implements.

You don't necessarily need a tractor, that depends on what operations you need to perform. If you don't have a good brush cutter, or have a local guy to hire with one, then it may be a good purchase for you for that property. I like the Honda 4 stroke with about 10" tri-blade, maybe 8,000 baht (or more now). I can recommend a shop in Chiang Mai that services them too, but I don't know elsewhere. Protect yourself, especially your eyes, I hit a rock once that kicked up and broke my glasses, close call. I'm already half deaf from 50 years of chain saws, don't need to lose an eye. I use a face shield or at least safety glasses ever since. I have a friend who hit and flung a piece of metal that imbedded in his leg bone. Don't try to cut too low or you get into the rocks and other stuff.

Cut the weeds early and frequently before they go to seed and get big and woody. I had 10 rai in Chiang Mai with mango and longan orchards, veggies, papayas, bananas, limes, landscaping with palm and plumeria collections, and a one rai open field. I had a neighbor guy with a Robin 2 stroke krueng tat ya (cheaper and good, a local favorite) and we would do dueling brush cutters for a day or two at a time to stay on top of it.

[nlimwa]

Hey everyone,

I have read this thread with great interest, lots of great info on here, thank you all for sharing your knowledge!

We have just got some land in Chiang Mai which is basically a very sandy field. I am not sure if they actually dumped sand on top or whether it is just very sandy soil - there are water erosion signs so I know its freshly done. Now is a good time to plant, but before I run off to acquire seed. I just wanted to ask if anyone else had very poor sandy soil, and if so what did you find to work best?

Thanks very much!

[drtreelove]

There is a recent thread on Plants, Pets and Vets Forum on this subject.

http://www.thaivisa.com/forum/topic/915032-garden-built-on-sand/

Dig a hole,to determine your soil profile, or better yet several holes around your land with sandy surface, . If the sand layer is not too deep, less than six inches, you can hire a rototiller to mix the sand with the clay subsoil. And you can incorporate compost or grow a cover crop first and till that in too while you're at it.

[nlimwa]

Great thread link, thanks!