Anion exchange membrane soil nitrate predicts turfgrass color and yield.

Desirable nitrogen (N) management practices for turfgrass supply sufficient N for high quality turf while limiting excess soil N. Previous studies suggested the potential of anion exchange membranes (AEMs) for predicting turfgrass color, quality, or yield. However, these studies suggested a wide range of critical soil nitrate-nitrogen (NO3-N) values across sample dates. A field experiment, in randomized complete block design with treatments consisting of nine N application rates, was conducted on a mixed species cool-season turfgrass lawn across two growing seasons. Every 2 wk from May to October, turfgrass color was assessed with three different reflectance meters, and soil NO3-N was measured with in situ AEMs. Cate-Nelson models were developed comparing relative reflectance value and yield to AEM desorbed soil NO3-N pooled across all sample dates. These models predicted critical AEM soil NO3-N values from 0. 45 to 1.4 micro g cm-2 d-1. Turf had a low probability of further positive response to AEM soil NO3-N greater than these critical values. These results suggest that soil NO3-N critical values from AEMs may be applicable across sample dates and years and may serve to guide N fertilization to limit excess soil NO3-N

Cornell Field Crops and Soils Handbook

A companion to the Cornell Guide for Integrated Field Crop Management, this handbook serves as a resource reference and contains expanded background information, research findings, and the reasoning behind the recommendations for climate, soil management, soil fertility, grain and forage crop production. This reference also includes a section on integrated pest management for weeds, insects, and diseases

Nutrient Applications Reported by Farmers Compared with Performance‐Based Nutrient Management Plans

Bravo-Ureta, B (Bravo-Ureta, Boris)2,3;2. Univ Connecticut, Dep Agr & Resource Econ, Storrs, CT 06269 USA 3. Univ Talca, Dep Agr Econ, Talca, ChileThis study had two main objectives: (i) to evaluate how well farmers implemented nutrient management plans (NMPs) by comparing the farmers' reported practices with the recommended management for manure and fertilizer; and (ii) to evaluate whether the management of manure and fertilizer had significant effects on the nutrient status of soil and corn tissue tests. The analysis relied on data from four dairy farms that had 5 to 7 yr of records at the field level. The farmers chose to apply the recommended amount of fertilizer P from 50 to 100% of the fields. The amount applied was often only 10 to 20 kg P2O5 ha(-1) different from the recommended amount. The farmers applied the recommended amount of fertilizer N from 40 to 71% of the fields when the pre-sidedress soil nitrate test (PSNT) was used for the recommendation, but only 1 to 21% of the fields received the recommended amount when the yield goal method was used. These data suggest that the farmers trusted a fertilizer recommendation developed from a soil test more than they trusted a nonsoil test recommendation. Only a small percentage of fields (3-37%) received the recommended amount of manure N and P. Variability in the amount of residual N available from previous manure applications caused great variation in the PSNT and corn stalk nitrate values (CSNT). This variation in N availability in fields indicates that a number of years of data are needed before the PSNT and the CSNT can be used to objectively evaluate the performance of an NMP