Maximizing Wheat Production

Achieving higher grain yields requires a combination of good genetics with a good environment. The full genetic potential of many crops is severely limited by poor environmental conditions especially due to poor soil structure, too much or too little water, and the availability of essential nutrients. Research shows that wheat yields can be increased 50%-100% by improving the soil environment resulting in 2-3X higher root growth and 3-4X higher tillers, resulting in more upright plants for higher photosynthesis and wheat plants with less disease and insect pressure. Good soil health allows each wheat plant to maximize its yield potential.

Several management factors that increase wheat yields include plant spacing (related to plant tillers), adequate aeration (oxygen), and high soil organic matter or compost. Wheat seed that is planted too close together inhibits root development and wheat tiller formation due to the competition for water and nutrients. For early wheat planting, close to the Hessian fly free date, less seed is needed than for later planting dates. One healthy wheat plant with 4-5 or more tillers yields more than 3 unhealthy wheat plants with one tiller. The seed kernel count on each tiller in healthy plants may be 2-4X higher than unhealthy plants. To increase wheat tillers, plant early to take advantage of warmer temperatures and longer day length which promotes faster plant leaf and root growth, and larger day/night temperature differences which reduces night respiration and increase plant sugars for optimal growth. With wider plant spacing (lower wheat seed population), there is less root competition which enhances wheat canopy growth to increase photosynthesis 15-18%, resulting in more tillers.

In order for this strategy to work, soils need to be well aerated and have good soil structure. Adding compost to the soil, especially around the seed, has been found to supply higher levels of zinc, copper, manganese, iron, and sulfur as balanced nutrients which promotes more plant enzymes, higher plant photosynthesis, and higher yields. Compost greatly enhances microbial activity which release plant available nutrients to elongating wheat roots. High soil organic matter or compost enhances silica in the form of silicone in wheat straw, decreasing wheat lodging and increases wheat straw production by 18%. Compost improves soil permeability allowing for more soil oxygen, promotes a balanced fertilizer with many micronutrients, and greatly increases microbial abundance for more nutrient availability. Compost also improves the soil water holding capacity so that dry conditions are less of a factor. Wheat with compost or high soil organic matter stays green longer in the late spring/early summer, adding to grain yield. Using a combination of inorganic commercial fertilizer with some compost has been shown to maximize wheat yields.

Human bodies harbor many microbes and now we find that plant tissues do the same thing. Microbes (fungi, bacteria) growing inside the plant are called endophytes and they assist the plant in expressing its full genetic yield potential. Compost seems to be an ideal substance to promote higher endophyte plant production; promoting more roots, tillers, and increased grain weight. Research shows that 20-30 proteins and enzymes are significantly higher in plants with endophytes, which increases the activation of genes for higher growth and higher crop yields. Microbes outside the plant root increase available essential nutrients for plant uptake and growth while microbes inside the plant promote phytohormones to stimulate root development and higher root sugars to feed the root microbes. Microbes inside and outside the plant complement each other to promote a healthier plant just like goods microbes inside our human gut. Unfortunately, too much inorganic or commercial fertilizer (by itself) may have too high of a salt content and may not provide a balanced nutrient plant diet to promote optimal growth (unless the soil organic matter content or compost level is high).

Good soil health may not only translate into higher yields but improved nutrient quality in the seed. Healthy plants have higher levels of seed micronutrients which translates into nutrient dense seeds that weigh more (higher test weights). Healthy nutrient dense seeds have less broken kernels and the seed is less “chalky” which improves baking milling characteristics. Healthy plants also move essential microbes into the plant seed to improve seed germination and nutrient uptake at planting. An analysis of seed from unhealthy soils shows that many of these essential seed microbial populations may be greatly reduced or missing. Improving soil health is not only good for plant and seed health, it is also good for human health.