Many of the characteristics of common purslane that describe this species as a “weed” are also desirable traits for a living mulch. Common purslane was investigated as a living mulch in spring broccoli production in Connecticut and was compared with mechanical and chemical weed control, as well as black plastic mulch. Common purslane seed was broadcast prior to transplanting broccoli in late May 1993 and in early June 1994. Broccoli yields with the purslane living mulch were comparable to yields with conventional methods of weed management and with no reduction in crop quality. Common purslane living mulch was able to effectively compete with weeds in broccoli when between-row areas were kept relatively weed-free by hoeing or hand pulling during the first 2 weeks after broccoli transplanting. High levels of weed control and ground cover occurred when purslane became established between crop rows. Broccoli plants were tolerant of purslane living mulch and weeds up to a critical threshold level without a significant reduction in yield. Purslane living mulch established through periodic mechanical weed management was determined to be the most economical treatment in the study. While including purslane living mulch in a spring broccoli crop production system may be a novel approach to controlling weeds, the strategies involved in this system still rely on basic weed management principles.

Although crop production and weed growth could change if herbicides and fertilizer inputs were reduced, the short-term impact in an annual cropping system in the Northern Great Plains is not well understood. Data were collected from 14 sites in Saskatchewan, Canada, to investigate the influence of weed control method (cultural vs. herbicides) and N and P fertilizers on crop yield of fall rye, spring wheat, and barley, and the presence and number of weed species. Cultural weed control included 25% greater crop seeding rate, preseeding tillage closer to the time of seeding, and fertilizer N banding in closer proximity to the seed. Four weed species (wild oat, lambsquarters, wild buckwheat, and field penny cress) occurred more frequently in plots with cultural weed control compared with herbicide weed control for all cereal crops. However, straw and grain yields of all crops were unaffected by weed control method at all sites. The addition of fertilizer had a major impact on crop growth and some weed species. Green foxtail occurred more often in unfertilized compared with fertilized plots for all cereal crops. Straw and grain yields of all cereal crops were higher in fertilized compared with unfertilized plots. Crop yield response to fertilizer inputs was not consistent among sites for the three cereal crops. Producers making drastic reductions in fertilizer inputs may experience reductions in crop yields because of limited nutrient levels. However, the results indicate that herbicide inputs could be reduced or eliminated periodically with no short-term yield loss in cereal cropping systems.

Two field experiments were conducted from 1991 to 1996 on clay soils in central Sweden to provide information for improving soil fertility, minimizing N leaching, and increasing the benefits of ley to subsequent crops in organic farming. The results show that it is possible to calculate the amount of N mineralized during the 2-year period following incorporation of ley-crop residues, based on the proportion of incorporated organic matter stabilized in the more resistant humus fractions (i.e., the humification coefficient, calculated to be 35–40%), C:N ratios of the ley biomass, and ley age (humification appears to be higher in older crop residues). The fractions of potentially mineralizable N that are actually mineralized in the first and second years after ley incorporation vary depending on ley age and botanical composition and climatic conditions.

Sustainable production systems are needed to maintain soil resources and reduce environmental contamination on erodible lands that are incompatible with tillage-intensive operations. A long-term cropping systems comparison was established at Beltsville, Maryland, on a site with 2 to 15% slope to evaluate the efficacy of sustainable strategies compatible with reduced-tillage systems. All systems followed a 2-year rotation of corn the first year and winter wheat followed by soybean the second year. Treatments included (1) no-tillage system with recommended fertilizer and herbicide inputs, (2) crownvetch living mulch system with similar inputs to the no-tillage system, (3) cover crop system including a hairy vetch cover crop before corn and a wheat cover crop before soybean with reduced fertilizer and herbicide inputs, and (4) manure system including crimson clover green manure plus cow manure for nutrient sources, chisel plow/disk for incorporating manure, and rotary hoe plus cultivation for weed control. Results from the initial 4 years demonstrated the relative productivity of these systems. Corn yields were similar in the no-tillage and cover crop systems in each year; both systems averaged 7.8 Mg ha-1 compared to 5.7 Mg ha-1 in both the crownvetch and manure systems. Wheat yields were highest in the manure system in the first 2 years and in the crownvetch system in the last 2 years. Soybean yields were highest in the cover crop system in all years. The manure system usually had lower yields than the highest yielding systems, partly because of competition from uncontrolled weeds. Several measures of the efficiency of grain production were evaluated. The no-tillage system produced the most grain per total vegetative biomass throughout the rotation. The cover crop system produced the most grain per unit of external nitrogen input and, along with the no-tillage system, had the highest corn water-use efficiency. The cover crop system also recycled the most vegetative residues and nutrients of all systems. No single system performed best according to all measures of comparison, suggesting that trade-offs will be required when choosing production systems.

Residential household owners were surveyed in two different New Hampshire communities that varied in terms of population size, degree of rurality, and per capita income, each with no activities in land application of biosolids. Logit models were developed and logistic regression analyses were carried out for each community. The empirical results suggest that the perception by residents of the potential economic benefits and negative impacts from land application of biosolids can be very influential in achieving public acceptance. From a policymaker's viewpoint, this suggests the need for sound educational programs that explicitly describe the economic benefits, negative impacts, and potential risks that typically occur with land application of biosolids. Supportive studies are needed to complement the educational programs. These measures will allow residents to weigh the relative benefits and costs to determine their positions on this approach to management of biosolids and to discount emotional judgements and misinformation. The media needs to ensure that newspaper, magazine, and television reports are accurate and taken from reliable sources. Survey results suggest that the less volume of information presented by the media, the more supportive residents are of land application. Therefore, with such sensitivity by respondents to quantity of information, it is imperative that media outlets place high priority on the quality and accuracy of materials presented. Socioeconomic characteristics of the respondents did not influence attitudes toward acceptance or rejection of biosolids application, thus eliminating the difficulty that social stratification could cause in achieving acceptance.