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A watershed analysis of nonpoint-source pollution associated with sugarcane (Saccharum officinarum L.) production was conducted. Runoff water samples following major rainfall events from two representative sugarcane fields (SC1 and SC2) were collected and analyzed. The impact of runoff on two receiving water bodies, St. James canal (SJC) and Bayou Chevreuil (BC) in a drainage basin (Baratarian Basin), was studied. Results show that runoff flow/rainfall ratios at the SC1 were significantly higher (P < 0.0001, n = 14) than at the SC2, probably mainly due to higher sand content and higher infiltration rate of surface soil at the SC2. In runoff water samples, total suspended solids (TSS) showed a significant correlation with the concentrations of N and P. Sugarcane runoff showed a direct impact on the SJC and BC locations where seasonal variations of pollutant concentrations in the waters followed the patterns of runoff loadings. Swamp forest runoff (SFR) location showed a buffering effect of forested wetlands on water quality with the lowest measured pollutant concentrations. The ratios in total N/total P and in inorganic N/organic N in runoff waters indicated that fertilization in spring greatly contributed to the temporal increase of N loadings, especially in forms of inorganic N. Isotope signature of (15)N-nitrate in the water samples verified that the nitrate was derived from fertilizers and was consumed during transportation. Both N and P concentrations in the receiving water bodies were above the eutrophic level. During the study period, herbicide concentrations in the receiving water bodies rarely exceeded the drinking water standards.

Potential sources of error in analysis of vitamin A in animal feed and pet food are discussed. Errors arising during sample handling and preparation and those due to standards, calibration, sample size, hydrolysis, extraction, evaporation, detection, equipment calibration, and isomerization are addressed. Quality control practices are recommended, and safety considerations are outlined. A summary of systematic and random errors is provided.

Good sample preparation is an essential first step to almost all laboratory analytical procedures. The procedures presented are intended to stimulate interest in generic methods for performance testing of various steps in fertilizer sample preparation, including initial reduction of unground sample, grinding, and mixing. Sample reduction quality is measured by 2 types of procedures, the first using 2 sizes of glass beads for a more theoretical approach, and the second using 2 common fertilizer materials for a more empirical method. Grinding performance is measured by recovery and carryover methods, followed by particle size and uniformity estimates of the ground material. Mixing after grinding is tested by measuring time-to-blend of a segregated mixture.

Bioengineered reefs have been developed that enhance natural spatset of oysters Crassostrea virginica and other sessile organisms, and can be emplaced in appropriate coastal waters. These reefs encourage growth of desired organisms and, in areas where regeneration of oyster populations are needed, can in themselves constitute ecological restoration. However, in addition to hosting sessile organisms, these reefs, which have high porosities (material use is less than 20% of usual rock breakwaters), also allow juvenile fish to find shelter and may enhance sedimentation or reduce erosion. Engineering design has focused on optimizing growth of organisms, allowing potential harvest, reducing wave erosion, sequestering carbon for long periods (millennia), and assisting in coastal wetlands restoration. Growth of organisms is enhanced by providing larger amounts of surface area (more than twice the surface area compared to rock) and including attractants (agricultural byproducts which release nitrogen compounds), as well as by the geometry. Harvest could be made from such reefs, and, since they are engineered, they can be made more harvestable. Wave energy is reduced more as growth occurs, so this is a potential negative when first emplaced, but allows enhanced sustainability over time, while carbon is sequestered in shells long term. The current coastal settlement rate of ~1-2 cm/yr allows carbon sequestration that could offset millions of tons annually in large emplacements. Finally, coastal wetlands are enhanced both by reduction of erosion and by enhanced habitat for juvenile fish and plant species. The potential for ecological restoration has only begun to be explored.