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How does nitrogen work in the soil, and where does it come from when we don't have a bag of fertilizer to supplement it?

I've spoken many times on this subject at conferences and it was the main theme of my talk when I represented North America at the World's 1st Humus Experts Meeting in Vienna Austria back in 2013.   Most of the Nitrogen used by the vast tropical rain forests, or the fastest growing biomass place on Earth, the Coastal Redwood Forests of California, comes from the production of protein by the Free-Living Nitrogen Fixing bacteria in soil and the massive biomass structure of the mycorrhizal fungi.    The proteins as it breaks down in the soil into amino acids are the building blocks of life and the explanation of the Soil Food Web.  However, in order for those amino acids to enter a plant and be part of the nitrogen budget of the plant they must have the assistance of the mycorrhizal fungi.  It's much more efficient for a plant to uptake amino acids whose molecules include nitrogen needed to build tissues than to uptake just nitrogen minus the amino acid.   The problem with dep
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Understanding Biochar

Biochar is being promoted aggressively as the miracle product for fixing soil, but does it work and if so, how does it work?   And as a carbon product, is it better than our TerraPro?   This is my response to questions concerning Biochar.   There have been many products and many attempts to change the function of the geology of soil including adding substances to the site using products like compost, zeolite, adding a clay slurry to desert sand, Oxidized Lignite (also known as humate or leonardite), and Biochar.    Adding anything to a soil, attempting to change its structure, its bulk density, its water management, or its nutrient value all use either a  Mode of Action  or a  Mechanism of Action .    A Mode of Action is an anatomical change affecting living organisms, while a Mechanism of Action describes changes on a molecular level.   For example, putting compost into the soil provides nutrition to the soil biota, helping to support and possibly grow more biota, providing a Mode of

All About the Shantung Maple!

             The Shantung Maple ( Acer truncatum ) is also known as the Purple Blow Maple due to the color of its newly emerging leaves which are red-purple (see photo below). These young expanding red-purple leaves change to green as they mature. Leaves are small, about the size of Japanese Red Maple leaves, perhaps 3’-4’ wide at maturity.    The Shantung Maple grows 1′-2′ annually reaching 25″ tall and wide.    This is our tree for all planting situations. This Maple does well in heavy clay, sandy soils, full sun, or part shade. It can be planted in a lawn or next to a hot asphalt street (see photo below). It seemingly is a happy tree enjoying life wherever it is placed.    One place we would not recommend planting this tree is in a rockscape which is just too hot and inhospitable to support this beautiful tree.               A smaller tree, the Shantung Maple can be planted closer to structures. Its fall color is a brilliant golden yellow. The Shantung Maple produces a winged fruit

Autumn Sage

           Autumn Sage ( Salvia greggii ) is also commonly known as Cherry Sage owing to its flower color.  Autumn Sage is native to the Chihuahuan desert. It is a small, evergreen to semi-evergreen shrub reaching 2’-3’ tall and wide. It blooms repeatedly through summer until frost making it a great addition to the garden or xeric landscape. It has one inch red to pink flowers that are found on spikes up to 10 inches long and are attractive to hummingbirds (see photo below). The red and pink flowered varieties are the most common but Autumn Sage can also be found in white, yellow, and orange flowered types. Autumn Sage is very heat tolerant and best grown in full sun on well-drained soils. It is a low water use plant once established but flowers more regularly with extra water.    Care consists of late winter pruning to remove dead wood and dead tips to encourage lush regrowth (see photo below). Autumn Sage is hardy to USDA zone 6. Autumn Sage makes a colorful addition to the landscape

Desert Willows

The Desert Willow ( Chilopsis linearis ) is a small flowering tree grown for its orchid like flowers and tolerance to hot arid landscapes.  The Desert Willow is a New Mexico native tree that normally grows with multi-trunks to about 15′-18’ tall and wide. If pruned into a single-trunk tree it can grow much taller. This trees common name, Desert Willow, is given due to its willow-like leaves (photo). The Desert Willow is not related to other willows like Globe or Weeping. The Desert Willow is well suited for the xeric landscape or to cool down a west or south facing wall. In particularly hot areas, areas with low annual rainfall or where water is limiting the Desert Willow makes a great specimen tree because of its tolerance to these conditions. In hot, dry areas the Desert Willow is sometimes used as the sole landscaping tree (photo). It produces a light dappled shade due to its leaf and canopy structure that is ideal to cool down hot sun facing walls (photo). It produces orchid like f

Weed Identification: Silver-Leaf Nightshade

Silver-Leaf Nightshade ( Solanum elaeagnifolium ) is a perennial plant usually growing 8” to 20” tall. It is easily recognized by its silver green wavy leaves and stem color,   often thorny stems, and violet colored, star shaped flowers with protruding yellow stamens. Other common names for Silver-Leaf Nightshade are Prairie Berry, Silver-Leaf Nettle, and Satan’s Bush. Silver-Leaf Nightshade flowers from late spring into fall and is native to the Southwestern United States and into Mexico. It is considered a noxious weed in many states.  Silver-Leaf Nightshade is poisonous and toxic to livestock. Silver-Leaf Nightshade propagates from both rhizomes and seed found in berries. Green striped berries turn yellow or orange at maturity and then dry to brown.   Silver-Leaf Nightshade has an extensive root system     and can form colonies, which makes it difficult to eradicate.   If you have time and patience, Silver-Leaf Nightshade can be eradicated simply by digging it out, either by hand or

Wildflower Seeds Worth Collecting: Desert Marigolds

 The Desert Marigold grows abundantly in dry sandy or gravelly soils, high heat and full sun, with only the moisture that Mother Nature provides. The Desert Marigold is a small plant about 8" – 12” tall and 12” – 24” in width. Its foliage, both stems and leaves, are a hairy or woolly silver gray. The Desert Marigold produces abundant, showy, yellow daisy like flowers from spring until frost. Flowers contain both ray (outer ring with yellow petals) and disc (inner section without petals) flowers. After flower petals whither and the seed heads begin to dry, seeds can be harvested. Seeds mature from late summer through fall. Seeds are maturing now (October) and can be collected. Sow seeds immediately into your xeric landscape. The Desert Marigold makes a great addition to your xeric landscape or cactus garden due to its minimal water needs. The Desert Marigold is best grown in full sun, on dry mesas, sandy or gravelly soils, with low to no irrigation water. The Desert Marigold is har