County Snowfall Estimates, March 2007

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau. The Iowa Crops and Weather report released by the USDA National Agricultural Statistical Service.

County Snowfall Estimates, April 2007

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau. The Iowa Crops and Weather report released by the USDA National Agricultural Statistical Service.

County Snowfall Estimates, November 2007

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau. The Iowa Crops and Weather report released by the USDA National Agricultural Statistical Service.

County Snowfall Estimates, December 2007

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau. The Iowa Crops and Weather report released by the USDA National Agricultural Statistical Service.

County Snowfall Estimates, January 2008

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau. The Iowa Crops and Weather report released by the USDA National Agricultural Statistical Service.

County Snowfall Estimates, February 2008

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau. The Iowa Crops and Weather report released by the USDA National Agricultural Statistical Service.

County Snowfall Estimates, March 2008

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau. The Iowa Crops and Weather report released by the USDA National Agricultural Statistical Service.

County Snowfall Estimates, November 2008

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau. The Iowa Crops and Weather report released by the USDA National Agricultural Statistical Service.

County Snowfall Estimates, November 2008

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau. The Iowa Crops and Weather report released by the USDA National Agricultural Statistical Service.

County Snowfall Estimates, January 2009

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau. The Iowa Crops and Weather report released by the USDA National Agricultural Statistical Service.

County Snowfall Estimates, February 2009

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau. The Iowa Crops and Weather report released by the USDA National Agricultural Statistical Service.

County Snowfall Estimates, March 2009

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau. The Iowa Crops and Weather report released by the USDA National Agricultural Statistical Service.

County Snowfall Estimates, April 2009

Report produced by the The Department of Agriculture and Land Stewardship, Climatology Bureau. The Iowa Crops and Weather report released by the USDA National Agricultural Statistical Service.

Nitrate and ammonium in soil solution in tobacco management systems

Tobacco farmers of southern Brazil use high levels of fertilizers, without considering soil and environmental attributes, posing great risk to water resources degradation. The objective of this study was to monitor nitrate and ammonium concentrations in the soil solution of an Entisol in and below the root zone of tobacco under conventional tillage (CT), minimum tillage (MT) and no-tillage (NT). The study was conducted in the small-watershed Arroio Lino, in Agudo, State of Rio Grande do Sul, Brazil. A base fertilization of 850 kg ha-1 of 10-18-24 and topdressing of 400 kg ha-1 of 14-0-14 NPK fertilizer were applied. The soil solution was sampled during the crop cycle with a tension lysimeter equipped with a porous ceramic cup. Ammonium and nitrate concentrations were analyzed by the distillation and titration method. Nitrate concentrations, ranging from 8 to 226 mg L-1, were highest after initial fertilization and decreased during the crop cycle. The average nitrate (N-NO3-) concentration in the root zone was 75 in NT, 95 in MT, and 49 mg L-1 in CT. Below the root zone, the average nitrate concentration was 58 under NT, 108 under MT and 36 mg L-1 under CT. The nitrate and ammonium concentrations did not differ significantly in the management systems. However, the nitrate concentrations measured represent a contamination risk to groundwater of the watershed. The ammonium concentration (N-NH4+) decreased over time in all management systems, possibly as a result of the nitrification process and root uptake of part of the ammonium by the growing plants.

Adubação nitrogenada para milho com o uso de plantas de cobertura e modos de aplicação de calcário

O sistema plantio direto (SPD) é uma realidade na região dos Cerrados, mas alguns questionamentos persistem nesse tipo de manejo como o modo de realização da calagem e a dose de nitrogênio (N) a ser adotada em cultura comercial, em relação às culturas precedentes. Desse modo, objetivou-se avaliar modos de aplicar o calcário na implantação do SPD e o efeito de culturas de cobertura precedentes sobre a necessidade de adubação nitrogenada da cultura do milho, durante diferentes anos agrícolas. O delineamento experimental utilizado foi de blocos casualizados, em esquema fatorial 5 x 2 (modos de aplicação do calcário x culturas de cobertura) e posterior divisão em três subparcelas, referentes às doses de N (0, 90 e 180 kg ha-1). Foram avaliados quatro modos de aplicação de calcário: incorporado a 0-0,2 m, em out./2001; dose total em superfície aplicada, em out./2001; aplicação de 1/2 da dose, em out./2001, e 1/2, em ago./2002, na superfície; e aplicação de 1/3 da dose recomendada, em mar./2001, + 1/3, em out./2001, e 1/3, em ago./2002, também em superfície. Além de um tratamento testemunha (sem calcário) e duas culturas de cobertura, crotalária e milheto. Os diferentes modos de calagem não alteraram a produtividade de grãos de milho. O cultivo de milho após crotalária apresentou melhor desempenho e menor demanda de adubação nitrogenada, quando comparado ao cultivado após milheto.