Clonal variation in nutrient content in woody biomass of hybrid aspen (Populus tremula L. x P. tremuloides Michx.)

Abstract

Nutrient allocation, accumulation and above-ground biomass in grey alder and hybrid alder plantations

Abstract

Longitudinal Grinding and Transverse Grooving to Improve Frictional and Profile Properties, HR-1035, 1983

There are many miles of portland cement concrete pavement in Iowa that due to normal wear, and in some cases accelerated wear from studded tires, the surface has become polished resulting in less than desirable friction values. Retexturing the surface may be an economical way to re-establish desirable friction values. Retexturing by grinding with diamond blades and transverse grooving with diamond blades are two methods of rehabilitating p.c.c. surfaces. MU Inc. of Lebanan, Tennessee proposed to provide without charge to the Iowa Department of Transportation, one 1500 ft x 12 ft section each of three methods of texturing. They are longitudinal grinding, transverse grooving and longitudinal grinding followed by transverse grooving. A section of 1500 feet is needed to properly evaluate a texturing method. It was decided by Iowa DOT personnel that due to possible differential friction it would be undesirable to texture only one lane. The decision was made to do test sections of 1500 ft x 24 ft with the cost of the additional texturing paid by the Iowa DOT. Iowa also has areas where the p.c.c. pavement has faulted at the joints and cracks which results in poor riding quality. Methods of correcting the faulting are to underseal the pavement where needed and/or grinding the surface to eliminate the faulted areas. It was decided to include in this research project a section for profiling by grinding.

Variation in soil nutrient concentrations and bulk density within peatland forest sites

Abstract

Cohort profile: the Swiss HIV Cohort study.

The substantial recurrence rate of colorectal cancer following potentially curative resection has fuelled the search for effective adjuvant therapy. Previous trials using 5-fluorouracil (5-FU) as a single agent or in combination chemotherapy regimens have not demonstrated meaningful benefits, an impression reflected in the results of a meta-analysis encompassing large patient numbers. Newer developments utilizing intraportal chemotherapy and the combination of 5-FU and levamisole have resulted in lower recurrence rates and improved survival in patients with colon cancer. In advanced disease, the biochemical modulation of 5-FU by Leucovorin has been shown to prolong survival in some studies. Combined chemotherapy and radiotherapy or chemotherapy alone have showed promising results in rectal cancer. These developments have now been incorporated into ongoing trials.

Reduced tillage: influence on erosion and nutrient losses in a clayey field in southern Finland

Selostus: Aurattoman viljelyn vaikutus eroosioon ja ravinnehuuhtoumiin eteläsuomlaisella, savimaalla sijaitsevalla pellolla

Addition of stabilized wood ashes to Swedish coniferous stands on mineral soils : effects on stem growth and needle nutrient concentrations

Abstract

Critical values of nitrogen indices in tomato plants grown in soil and nutrient solution determined by different statistical procedures

The objective of this study was to establish critical values of the N indices, namely soil-plant analysis development (SPAD), petiole sap N-NO3 and organic N in the tomato leaf adjacent to the first cluster (LAC), under soil and nutrient solution conditions, determined by different statistical approaches. Two experiments were conducted in randomized complete block design with four repli-cations. Tomato plants were grown in soil, in 3 L pot, with five N rates (0, 100, 200, 400 and 800 mg kg-1) and in solution at N rates of 0, 4, 8, 12 and 16 mmol L-1. Experiments in nutrient solution and soil were finished at thirty seven and forty two days after transplanting, respectively. At those times, SPAD index and petiole sap N-NO3 were evaluated in the LAC. Then, plants were harvested, separated in leaves and stem, dried at 70ºC, ground and weighted. The organic N was determined in LAC dry matter. Three statistical procedures were used to calculate critical N values. There were accentuated discrepancies for critical values of N indices obtained with plants grown in soil and nutrient solution as well as for different statistical procedures. Critical values of nitrogen indices at all situations are presented.

Nutrient distribution in Picea likiangensis trees growing in a plantation in West Sichuan, Southwest China

Abstract

Iowa Manure Matters: Odor and Nutrient Management, May 1999, Vol. 2, no. 1

Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.

Iowa Manure Matters: Odor and Nutrient Management, Spring 2000, Vol. 3, no. 1

Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.

Iowa Manure Matters: Odor and Nutrient Management, Summer 1999, Vol. 2, no. 1

Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.

Iowa Manure Matters: Odor and Nutrient Management, Fall 2001, Vol. 4, no. 3

Iowa Manure Matters: Odor and Nutrient Management is published by Iowa State University Extension, with funding support from the USDA Natural Resource Conservation Service.