Browse on keywords: fertility WA variable fertilizer application
Search results on 10/21/18
2385. Hammond, M.W. and D.J. Mulla. 1989. Field variation in soil fertility: its assessment and management for potato production.. Presentation at 28th annual WA Potato Conference.
Spatial variability in potato fields for P and K is common and can lead to yield and quality reductions. The potential for variable fertilizer application allows for an efficient solution to the problem, both from an economic and environmental standpoint. The paper presents an example from an irrigated circle in the Columbia Basin. Fertility maps of the field are presented, showing the spatial variability. This information is used to delineate fertility management zones, which receive different rates. Fertilizer efficiency is shown for both the conventional and variable methods. The variable method increased fertilizer costs about $10/ac. on a 200' grid system, where both P and K were mapped. The program will normally increase profits well beyond this expense.
2396. Hammond, M.W. and D.J. Mulla. 1989. Intensive soil sampling and its use in fertilizer programs.. Presentation at 1989 Irrigated Agr. Fertilizer Conference.
Intensive soil sampling on a small grid in farm fields allows one to determine the spatial variability of nutrient levels and to adjust fertilizer applications accordingly. Data from 100, 200, and 400 ft. grids indicates that results from a 200' grid are adequate, but detail is lost at 400'. Soil information can be put on a computer chip for a given field and then used to drive variable fertilizer and pesticide application equipment.