Iowa Department of Veterans Affairs, Winter 2015

Iowa Department of Veterans Affairs Newsletter

Community College Leader Bulletin, Winter 2016, Vol. 5, Issue 4

Newsletter produced by the Iowa Department of Education, Community College unit. This report has information about staff, grants, statistical data, requirements and more.

The Annals of Iowa, Winter 2006, Vol. 65, no. 1

A quarterly journal of Iowa authors and their works produced by State Historical Society of Iowa.

The Annals of Iowa, Winter 2007, Vol. 66, no. 1

A quarterly journal of Iowa authors and their works produced by State Historical Society of Iowa.

The Annals of Iowa, Winter 2008, Vol. 67, no. 1

A quarterly journal of Iowa authors and their works produced by State Historical Society of Iowa.

The Annals of Iowa, Winter 2009, Vol. 68, no. 1

A quarterly journal of Iowa authors and their works produced by State Historical Society of Iowa.

The Annals of Iowa, Winter 2010, Vol. 69, no. 1

A quarterly journal of Iowa authors and their works produced by State Historical Society of Iowa.

The Annals of Iowa, Winter 2011, Vol. 70, no. 1

A quarterly journal of Iowa authors and their works produced by State Historical Society of Iowa.

The Annals of Iowa, Winter 2012, Vol. 71, no. 1

A quarterly journal of Iowa authors and their works produced by State Historical Society of Iowa.

The Annals of Iowa, Winter 2013, Vol. 72, no. 1

A quarterly journal of Iowa authors and their works produced by State Historical Society of Iowa.

CIRAS News, Winter 2016, Vol. 51, no. 2

CIRAS is to enhance the performance of Iowa industry, and associated entities, through education and technology-based services. This newsletter holds information regarding these services.

The Annals of Iowa, Winter 2014, Vol. 73, no. 1

A quarterly journal of Iowa authors and their works produced by State Historical Society of Iowa.

Winter pasture and cover crops and their effects on soil and summer grain crops

The objective of this work was to evaluate the effect of winter land use on the amount of residual straw, the physical soil properties and grain yields of maize, common bean and soybean summer crops cultivated in succession. The experiment was carried out in the North Plateau of Santa Catarina state, Brazil, from May 2006 to April 2010. Five strategies of land use in winter were evaluated: intercropping with black oat + ryegrass + vetch, without grazing and nitrogen (N) fertilization (intercropping cover); the same intercropping, with grazing and 100 kg ha-1 of N per year topdressing (pasture with N); the same intercropping, with grazing and without nitrogen fertilization (pasture without N); oilseed radish, without grazing and nitrogen fertilization (oilseed radish); and natural vegetation, without grazing and nitrogen fertilization (fallow). Intercropping cover produces a greater amount of biomass in the system and, consequently, a greater accumulation of total and particulate organic carbon on the surface soil layer. However, land use in winter does not significantly affect soil physical properties related to soil compaction, nor the grain yield of maize, soybean and common bean cultivated in succession.

A germination study of herbicide-resistant field poppies in Spain

Field poppy, Papaver rhoeas L., is a very common weed in winter cereals in North-Eastern Spain. Its control is becoming difficult due to expanding herbicide resistance. To control field poppies there are alternative strategies such as non-chemical control that take into account the weed emergence period. However, there is a lack of knowledge of P. rhoeas emergence patterns in semi-arid conditions. Thus, here we conducted pot experiments on the emergence of P. rhoeas. We aimed to describe the emergence period and to quantify the emergence of a susceptible and of a herbicide-resistant P. rhoeas population at two locations in Catalonia, Spain, from 1998 to 2001 and until 2004 at one of them. Therefore, pots containing seeds of both populations were established at the two locations and emergence was recorded monthly. We studied the origin of the population, the sowing location, the effect of cultivation and the sowing year. First, we found that the main emergence peaks in our experiments occurred in autumn, accounting for between 65.7 and 98.5% of the annual emergence from October to December, and only little emergence was recorded in spring. This emergence pattern is different from those found in the literature corresponding to Northern European countries, where in some cases main flushes occur only in autumn, in spring and winter or only in spring. The emergence was mainly affected by cultivation, but the effect of light stimulus was observed several months later. As a consequence, cultivation should be done in early autumn, promoting emergence during the whole autumn and winter so that emerged seedlings can be controlled before sowing a spring crop. Second, most experiments showed that the emergence was significantly higher in the first autumn than in the following seasons, e.g. 4.1% emergence in the first year and only 2.1, 2.3, 0.5 and 0.6% new emergence at one of the locations for the second, third, fourth and fifth years. Thus, after having a severe P. rhoeas infestation causing a big seed rain, emergence should be stimulated by autumn cultivation in the following season and seedlings controlled by trying to deplete the soil seed bank as much as possible. Despite the fact that emergence will be staggered throughout several years and that there was a significant relationship between rainfall and emergence, so that dry years will cause a smaller emergence rate of the weed, these findings define a cultural management strategy to reduce P. rhoeas infestations and to contribute to integrated weed management strategies combining it with other tools.