Wood Chip Mulch Research Articles

Effects of a Deep Layer of Mulch on the Soil Environment and Tree Root Growth

After two years, no detrimental effects were found from application of 0.45 m (18 in) of wood chip mulch over soil in which the roots of trees were growing. Soil temperature, moisture and oxygen diffusion rate (ODR) were similar to soil without mulch. Root density in mulched soil was not different from unmulched soil; additional roots had proliferated into the mulch.

Reduction of Oak Chlorosis with Wood Chip Mulch Treatments

Wood chip mulch and ammonium sulfate treatments around urban white oaks (Quercus alba) were associated with favorable changes in soil properties. Bulk density and pH were lower, and moisture content was higher under the mulch. Fine root development and number of mycorrhizal roots were also increased. Foliar manganese increased and phosphorous decreased. These changes were associated with a reduction of interveinal chlorosis.

Factors affecting establishment of one-seed juniper (Juniperusmonosperma) on surface-mined lands in New Mexico

Containerized one-seed juniper (Juniperusmonosperma (Engelm.) Sarg.) were planted on two northern New Mexico mine spoils to evaluate effects of establishment methods and postplanting site conditions on seedling survival and growth. Establishment factors included planting date, mulch, fertilizer regimes, and seedling protection. Wood chip mulch and animal protection provided by rigid plastic mesh tubes or plastic netting improved juniper survival, growth, or both, depending on the study. The forms and rates of fertilizers tested provided no benefits and sometimes decreased survival. Juniper fertilization at planting stimulated the growth of reseeded grass and resulted in greater competition. Perennial weeds that invaded a mechanically cleared planting site also reduced juniper growth and survival. Results point to the need to consider the adverse effects associated with fertilization, time of planting, and order of grass and juniper revegetation.

Yield Component Responses of ‘Hull Thornless’ Blackberry to Nitrogen and Mulch

Abstract The response of ‘Hull Thornless’ blackberry (Rubus spp.) to annual applications of three N rates (0, 41, and 123 kg N/ha) and straw or wood chip mulch plus 41 kg N/ha was studied. Pruning weight per plant increased linearly with increasing N rate in 1986 and 1987 and with straw mulch in 1987. Plants mulched with wood chips had the largest mean cane cross-sectional area, while neither N rate or straw mulch had an affect. Number of lateral branches per cane was not affected by any treatment. Yield increased linearly with N rate. Plants that received straw mulch produced yields that were greater than or equal to the high N rate. Mean fruit weight increased in response to straw mulch and increasing N levels in 1986, but only to the straw mulch in 1987. The number of flowers per cane and per inflorescence increased with increasing N rate, but inflorescence number per cane and fruit set were not affected. As N rates increased, yield per square centimeter of cane basal cross-sectional area increased. Both mulches decreased inflorescence number per square centimeter of cane basal cross-sectional area, but did not influence any other components of yield. Mean cane cross-sectional area, lateral branches per cane, inflorescences per cane, flowers per inflorescence, and mean fruit weight were significantly and positively correlated with yield per plant in 1987. Averaged over years, as the fertilizer N rate increased, primocane foliar N content increased, P declined, and K, Ca, Mg, and Mn were not affected. Mulching had no effect on nutrient element content.

Wood Chip Mulching Around Maples: Effect on Tree Growth and Soil Characteristics

Studies were conducted to evaluate the effect of wood chip mulch on tree growth, soil properties and certain soil microorganisms. Plots were established with red and sugar maples on a clay loam soil and silver maples on a sandy loam soil. Mulched silver maples on the sandy loam soil had significantly greater height, diameter, root and current-year shoot growth than those not mulched. Only current-year shoot growth of the mulched red and sugar maples was significantly greater than the non-mulched ones on the clay loam soil. On mulched plots on the clay loam, soil moisture remained higher throughout the study, and soil temperature was lower during the spring and summer. Most soil physical and chemical properties were unaffected after one year of the mulch treatment, as were population levels of two potential disease-causing fungi and plant parasitic nematodes in the clay loam.