322 Scharenbroch and Watson: Wood Chips and Compost Improve Soil Quality and Increase Growth Table 1. Amounts of total N, Bray P, exchangeable K, total C, total bacteria, and total fungi added per year and the mois- ture, pH, and microbial respiration rate of these treatments: water control (NULL), commercial biological product (CBP), aerated compost tea (ACT), NPK fertilizer (FERT), compost (COMP), and wood-chip mulch (WC). Response Moisture (%) pH (1:1) Total N (kg 100 m-2 Bray P (kg 100 m-2 Exch. K (kg 100 m-2 Total C (kg 100 m-2 Micr. resp. (mg kg-1 Total bact. (kg 100 m-2 Total fungi (kg 100 m-2 ) ) ) ) d-1 ) ) ) NULL n/a 6.61 4.8E-5 6.1E-9 1.2E-8 1.1E-3 1.50 6.1E-10 6.1E-11 CBP n/a 7.33 0.0741 7.0E-5 2.7E-5 1.22 19.6 0.420 7.0E-3 rice powder. During the 24-hour brew cycle, dis- solved oxygen, temperature, pH, and electrical conductivity were measured every hour. Dissolved oxygen remained above 6 mg kg-1 value of 8.4 mg kg-1 , with a mean Mean temperature, pH, and electrical conductiv- ity were 24°C, 8.1, and 560 µS cm-1 throughout the brew cycle. , respectively. On average (18 brews) the ACT contained only a fraction of what was in the compost itself: 2,688 mg bacteria kg-1 , 50 mg fungi kg-1 , 8 ciliates g-1 diameter of 3 µm), 200 flagellates g-1 bae g-1 , and 0.1 nematodes g-1 (mean hyphae , 140 amoe- . Upon completion of brewing, the ACT concentrate was diluted at a ratio of 1:4 (1 part ACT concentrate to 4 parts water) and immediately applied to plots as a soil drench. Applications were performed in the morning and not during periods of full sun. The commercial biological product (CBP) con- tained the following microbes: Bacillus azotofixans (33,250 mg kg-1 ), B. megaterium (33,250 mg kg-1 (33,250 mg kg-1 thuringinensis (33,250 mg kg-1 viridis (665 mg kg-1 (3,325 mg kg-1 ), B. subtilis (33,250 mg kg-1 ), and Trichoderma harzianum ), Streptomyces griseo- ). The CBP also contained malto- dextrin (48%), yeast extract (5%), soluble seaweed (13%), humic acids derived from leonardite (17%), precipitated silica (8%), leonardite extract (6%), and polyethylene glycol (3%). The CBP was applied as a soil drench with water at 840 L 100 m-2 The NPK fertilizer contained 30% elemental N yr-1 . K or 7% soluble potash (K2O). The fertilizer N source O5 (20% water insoluble synthesized N and 10% water- soluble synthesized N), 4.4% elemental P or 10% available phosphoric acid (P2 ), and 5.8% elemental is urea-formaldehyde, P source is monopotassium phosphate, and K source is monopotassium phos- phate. The fertilizer was also applied as a soil drench. ©2014 International Society of Arboriculture ), B. licheniformis (33,250 mg kg-1 ), B. polymyxa ), B. ACT n/a 8.10 0.0773 1.9E-3 3.4E-5 1.76 18.8 0.565 0.011 FERT n/a 7.34 1.95 0.280 0.369 1.63 11.2 4.8E-5 6.4E-7 COMP 26.2 7.60 0.385 0.0688 0.0343 5.25 26.6 8.22 4.67 WC 9.7 5.91 0.527 0.0560 0.0410 20.25 30.6 4.05 3.04 McHenry, Illinois, U.S.) contained 4,698 mg bacteria kg-1 3.0 µm), 123,831 flagellates g-1 123 ciliates g-1 , and 2.82 nematodes g-1 The compost (Midwest Organics Recycling, , 2,670 mg fungi kg-1 (mean hyphae diameter of , 5,756 amoebae g-1 (analyses , performed by Soil Foodweb, Inc., Corvallis, Oregon, U.S.). The mulch was double-ground hardwood chips. Average chip size was 2 cm in length by 0.5 cm thick. The mulch contained 1,000 mg bacteria kg-1 , 750 mg fungi kg-1 3.0 µm), 1,900 flagellates g-1 ates g-1 (mean hyphae diameter of , 600 amoebae g-1 , and 0.5 nematodes g-1 , 5 cili- . Mulch was applied annually in May to a 15 cm depth. Compost was applied annually in May as a 2.5 cm topdressing. Soil Sampling and Characterization Soil bulk density (Db) was determined on 06/02/2011. A 7.24 cm wide by 7.10 cm deep undis- turbed core was extracted from each plot. Soil was sieved, homogenized, and dried in an oven for 48 (K) via atomic adsorption spectroscopy (Model A5000, Perkin Elmer Inc., Waltham, Massachusetts, U.S.) (Schollenberger and Simon 1945). Phosphorus (P) was determined with the Bray P-1 extraction hours at 105°C. Material (roots, rock, etc.) greater than 2 mm was removed and its volume determined for bulk density corrections for non-soil material (Topp et al. 2008). On 10/06/2011, five 2.5 cm soil cores (0 to 15 cm depth) were collected at random points from the 120 plots and returned to the labora- tory for characterization. In the laboratory, soil sub- samples were weighed, dried for 24 hours at 105°C, and reweighed to calculate gravimetric soil mois- ture (Topp et al. 2008). Soil pH was measured in 1:1 (soil:deionized) water pastes (Model Orion 5-Star, Thermo Fisher Scientific Inc., Waltham, Massachu- setts, U.S.). Soil samples were extracted with 1 M NH4 OAc (pH 7.0) for determination of potassium
November 2014
| Title Name |
Pages |
Delete |
Url |
| Empty |
Search Text Block
Page #page_num
#doc_title
Hi $receivername|$receiveremail,
$sendername|$senderemail wrote these comments for you:
$message
$sendername|$senderemail would like for you to view the following digital edition.
Please click on the page below to be directed to the digital edition:
$thumbnail$pagenum
$link$pagenum
Your form submission was a success. You will be contacted by Washington Gas with follow-up information regarding your request.
This process might take longer please wait
