Bilingual children with reduced exposure to one or both languages may have language profiles that are apparently similar to those of children with developmental language disorder (DLD). Children with DLD receive enough input, but have difficulty using this input for acquisition due to processing deficits. The present investigation aims to determine aspects of adjective production that are differentially affected by reduced input (in bilingualism) and reduced intake (in DLD). Adjectives were elicited from Dutch–Russian simultaneous bilinguals with limited exposure to Russian and Russian-speaking monolinguals with and without DLD. An antonym elicitation task was used to assess the size of adjective vocabularies, and a degree task was employed to compare the preferences of the three groups in the use of morphological, lexical, and syntactic degree markers. The results revealed that adjective–noun agreement is affected to the same extent by both reduced input and reduced intake. The size of adjective lexicons is also negatively affected by both, but more so by reduced exposure. However, production of morphological degree markers and learning of semantic paradigms are areas of relative strength in which bilinguals outperform monolingual children with DLD. We suggest that reduced input might be counterbalanced by linguistic and cognitive advantages of bilingualism.

A 2-yr study was conducted near Mead, NE, to determine the interaction of six corn (Zea mays) hybrids having different heights and leaf angles and four herbicide rates on velvetleaf (Abutilon theophrasti) and green foxtail (Setaria viridis) biomass rating and seed production. Corn hybrid grain yields averaged over herbicide rates differed by up to 1,100 kg/ha in 1993 and 3,000 kg/ha in 1994, yet similar grain yield reductions occurred for all hybrids as herbicide rate decreased. Corn hybrids differed in suppression of weed growth and seed production, but suppression differences among hybrids were not consistent across years. Plots with the very tall, erect-leaf hybrid had 7.4 velvetleaf plants/m2, whereas other hybrids had 8.6 to 10.1 plants/m2. Plots with the very tall, erect-leaf hybrid also produced the lowest quantity of velvetleaf seeds of 23,100 seeds/m2 versus 25,100 to 30,700 seeds/m2 for plots with other hybrids. Erect-leaf hybrids suppressed weeds more effectively than horizontal-leaf hybrids. Corn hybrids had less effect on early- Fand late-season weed densities and biomass ratings and on seed production than herbicide application. Selection among current corn hybrids as a tool in integrated weed management will have a small or inconsistent influence on weed suppression.

Concern over the consequences of increased weed seed inputs to the soil seed bank during the transition period from conventional to organic production is one obstacle to grower adoption of reduced input and nonchemical weed management strategies. An 11-yr study was established in southwest Montana to investigate the effect of a single pulse of wild oat seeds on subsequent seed bank dynamics. In 1993, wild oat seeds were sown at five densities (0, 20, 80, 320, and 800 seeds m−2) in eight wheat–small grain cropping systems that differed in the number of crops in rotation and fallow periods. Wild oat seed banks were measured each spring from 1994 to 2004 in half of the cropping systems and from 2001 to 2004 in all eight systems. In 1994, seed bank densities in response to the pulse were as much as 11 times higher than controls that received no seeds in 1993. By 1996, after mechanical fallowing of all cropping systems, wild oat seed bank densities were not significantly different from densities in control plots regardless of the size of the initial seed pulse and remained so through 2004. These data suggest that increases in wild oat seed inputs during the organic transition period will have relatively few long-term agronomic effects on the dynamics of wild oat seed banks in these systems. In addition, wild oat seed banks may be constrained by factors other than cropping sequence when herbicides are not used, such as possible density-dependent regulation as a result of increased soil pathogen attack and seed predation.

Developing reduced-input agroecosystems is a challenge to researchers and practitioners in a number of disciplines. In particular, because of the complexity of managerial inputs, understanding the effects of decreases in levels of one or several inputs presents a difficult experimental problem. Moderate reductionism is proposed as an appropriate hierarchical analysis, which first characterizes system level behavior and then explains it in terms of system components and their interactions. An example is given using reduced nitrogen fertilizer inputs; higher nitrogen use efficiency at lower levels of input is explained by increased nutrient recycling between soil and plant subsystems. Transition from conventional to reduced-input management involves changes in both economic and ecological properties of agroecosystems. Biological, chemical and physical changes, including increased species diversity, tighter nutrient recycling, and longer-term perennial effects, may parallel ecological succession. Hypothetical trends for several such changes are discussed.