Plant Nutrient Flow in the Managed Pathways of an Intensive Dairy Farm

Abstract

The magnitude, and spatial and temporal patterns of nutrient flow in the managed pathways of a farm are related to farm management decisions and interact with the biological processes of the farm. These descriptions of nutrient flow can be part of a nutrient management process that is consistent with the specifics of individual farm operations and particular farm performance goals. Nutrient flow in the managed pathways of a Pennsylvania dairy farm was measured at farm, field, and livestock unit boundaries using on‐farm equipment scales, farm records, and material sampling and analysis. Farm nutrient inputs of N, P, and K were twofold or more greater than outputs of these nutrients in the managed pathways. The temporal distribution of flows was closely related to the livestock activities on the farm. Manure storage capacity and crop developmental stage were significant factors influencing the timing of nutrient flows to and from the fields. Nutrient inputs and outputs in the managed flows at the boundary for the set of all fields were approximately equal except for the negative calculated crop available N balance. However, the range in balances for individual fields was large. Manure N and potential biological N fixation were not used efficiently on this farm due primarily to the volatilization of N from manure and the application of manure to alfalfa. Additions of nutrients to the farm in the managed flows decreased by 26, 60, and 43% for N, P, and K, respectively, in the 2nd yr of the study due primarily to less purchased animal feeds.

Variability in Optimum Nitrogen Rates for Maize

“…Ideal nutrient management would provide a balance between nutrient input and output over longer periods of time (Bacon et al, 1990). Several factors affect grain yield, such as growing season, soil fertility, soil moisture, and environmental changes year to year.…”

Nitrogen turnover on organic and conventional mixed farms

“…A study of N turnover on a Pennsylvania dairy farm by Bacon, Lanyon and Schlauder (1990) also stressed the importance of interactions between the livestock unit and nutrient recycling via fodder crops to assess the possibilities for reducing nutrient loss. They suggested combining farm level N flow with more detailed in-formation on nutrient flows through the herd and individual fields, because these are the management units of the farm.…”

“…The interactions between the farmer, the herd and crop production must all be considered to understand agricultural N loss (Conway 1987;Bacon, Lanyon and Schlauder, 1990;S~rensen and Kristensen, 1992;Edwards et al, 1993).…”

Balance de nitrógeno en fincas para la producción de leche en Costa Rica.

“…En este sentido, utilizando los datos reportados por Kuipers et al (1999), Domburg et al (2000), Laws et al (2002), Spears et al (2003), Herrero et al (2006) y García et al (2007 En general, el balance de N fue positivo para todas las fincas, lo que indica que ingresa más N del que sale de ellas en forma de producto (principalmente leche y algo de carne). Diversos autores han reportado eficiencias globales que oscilan entre 15% (Aarts et al, 1992) y 46% (Bacon et al, 1990). El promedio de eficiencia encontrado en el presente estudio fue de 35%.…”