Growing biomass in arid environments

Hola,

Estoy trabajando con organizaciones comunitarias en Perú en la región del bosque seco de Tumbes-Piura. Recibimos poco más de 100 mm de lluvia al año. La mayoría de los meses reciben 0 mm de precipitación.

Obtuve excelentes resultados trabajando con Echo Seeds en Tailandia, pero este es un entorno completamente diferente. Mis preguntas:

  1. ¿Tiene experiencias positivas con cultivos forrajeros o cultivos de cobertura de abono verde u otros cultivos para biomasa en ambientes hiperáridos?

  2. ¿Puede recomendar cultivares del catálogo de semillas Echo que puedan sobrevivir en ambientes extremadamente secos?

Thomas Jefferson Rutherford

Hello,

I am working with community-based organizations in Peru in the Tumbes-Piura dry forest region. We get little more than 100mm of rain per year. Most months get 0mm of precipitation.

I had excellent results working with Echo seeds in Thailand, but this is a completely different environment. My questions:

  1. Do you have positive experiences growing fodder crops or green manure-cover crops or other crops for biomass in hyper-arid environments?

  2. Can you recommend cultivars from the Echo seed catalogue that could survive extremely dry environments?

That’s an extremely low quantity of rain to try and grow plants. My advice would be to focus on deep-rooted perennials rather than to try and grow annual cover crops. FMNR would be a good approach if you have existing stumps and native perennials in the area.

Neil

2 Likes

Seems like a good option to see what is growing wild there. It would be adapted to the local environment.

Thanks, Neil. That’s all good advice. The organizations that I’m assisting have various needs. FMNR and advice about regenerative grazing all welcome.

But the immediate issue is establishing biomass for backyard/container gardening and composting. There is very little available organic material for improving the soil – either for maintaining existing valued plants (mesquite, a species of caper, yucca, aloe) or for establishing backyard gardens or containers. Youtube suggests a big fat potting soil budget; but the people around here do not have the budget to avail themselves of such advice, lol.

Our idea is to grow green manure and cover crops to produce biomass to improve the existing garden plots, to begin container gardens and to produce compost. I’m collecting dry (mummified?) horse manure from the local herd, and the households produce abundant kitchen scraps.

So we are really wondering which gm-cc crops from the Echo catalogue would be most appropriate for the arid coast of northern Peru. The crop-selection tool is helpful. Thanks again for the thoughts.

Here is the list of “mulch crops” that we plan to order:

Hyper arid mulch crops

Beginning with most drought-tolerant

  • Slender Leaf Rattlebox (Crotalaria ochroleuca)
  • Horse Gram (Macrotyloma uniflorum)
  • Cowpea (Vigna unguiculata subsp. unguiculata)
  • Siratro (Macroptilium atropurpureum)
  • Lablab (Lablab purpureus)
  • Jack Bean (Canavalia ensiformis)
  • Pigeon Pea (Cajanus cajan)
  • Rice Bean (Vigna umbellata)
  • Fava Bean (Vicia faba)
  • Runner Bean (Phaseolus coccineus)
  • Hairy Vetch (Vicia villosa)
  • Sunn Hemp (Crotalaria juncea)
  • Mung Bean (Vigna radiata)
1 Like

Hi Jeff,

I agree with most of what others have shared here - it seems you are very dry for annual crop production by itself. Of the crops you listed the most arid-suitable are horse gram, jack bean (does need a few good rains for germination and root elongation), mung bean, and some varieties of pigeon pea or cowpea (short duration). More arid legumes that ECHO does offer from the seed bank include tepary bean (Phaseolus acutifolius) and butterfly pea (Clitoria ternatea).

Hello.
I am also interested in growing biomass in arid soil coupled with 3 months rain in year central highland Madagascar. The species you listed are very interesting at least for those that I know and that are similar to what we have: same genus but different species.
I just have a couple of questions:

  • what type of fertilizer will you be using to grow them in the arid soil and what is the minimal quantity to make it thrive?
  • what the plan for other species for the next year(s) on the parcel where you are going to put those drought-tolerant species?
    Thanks

Hi Jean,

Highland Madagascar must be fascinating. Coastal northern Peru is also a very dry and challenging place, but also fascinating. I found the species using the Echo seed catalogue calculator, which is a very helpful tool. Some of the green manure crops on my list I grew in monsoon northern Thailand. We had ample irrigation, but others did not and the crops did well.

I am working with different organizations and they all have different objectives. They cannot afford commercial fertilizer – even if they want it – so part of the idea of growing biomass crops is to produce compost to use as a natural fertilizer. And over time to build humus to aid their existing and precious plants.

One of their common objectives is to aid communities to develop backyard food gardens and container gardens. With no access to potting soil for nurseries or containers, we have to go from scratch. In some cases they have access to graywater, so the biomass is to help with annuals, herbs and to get drought-tolerant perennials established. During the brief rainy season – coming soon! – there is a brief explosion of growth. One idea is to get plants established and mulched to take advantage of that brief rain window. What the communities want to grow depends on their reasonable, ecologically grounded desires and expectations.

One approach I learned from permaculture and employed in Thailand is the growth of green manure crops like pigeon pea as companion plants for more commercially valuable plants like mango or pineapple. The approach is called chop-n-drop, in which the pigeon peas are cut back regularly and the biomass used as mulch around the mangoes or other target crops. Then at a certain point the plants are left to produce seed for consumption (in the case of pigeon peas and some other legumes) or for further planting. It is a hard sell to argue to local farmers that the crops are grown in order to be dropped on the ground. But the logic of feeding the soil to feed your target crops to feed your community – well, it’s a powerful logic that is worth disseminating.

As always, small trials should be employed, so that we do not demonstrate too much failure.

Good luck!