Proceedings
Year
| Filter results27 paper(s) found. |
|---|
1. A Comparison of Producer Adoption of Precision Agricultural Practices in Denmark, The United Kingdom, and Nebraska in the United StatesWhile a lot of research and commercial development has taken place in precision agriculture in recent years there is little information available about the experience and opinions of the producers who are trying to make it pay its way in the field. Information about producer experiences in precision agriculture would be useful in guiding hture research and development in both the public and private sectors. Important questions could include: - what types of precision agriculture practices are pr... |
2. Adjusting N Recommendations Based on a Previously Grown CropNitrogen recommendations in North Dakota are based on a yield goal multiplied from some empirically derived factor in a linear formula. There are a three adjustments to the N recommendations that result form these formulas (Franzen and Cihacek, 1996). They are the soil test nitrate-N to some depth, a sampling date adjustment ifthe sampling was conducted in the fall prior to September 15, and a previous crop credit. Two of these three adjustments are based on some knowledge regarding mineralizati... |
3. Corn and Soybean Response to Potassium Fertilization and PlacementI\ncreased adoption of conservation tillage, evidence of large within-field nutrient variability, and an apparent increase in the Frequency of crop potassium (K) deficiency symptoms in Iowa and other states have prompted questions about the effectiveness of current soil-test K interpretations and fertilizer recommendations. These questions relate to fertilizer placement and management of within-field nutrient variability. Broadcast placements are less costly than banded placements but they seem ... |
4. Deep Tillage in a Corn-Soybean Production SystemMany crop producers in the Midwestern United States are currently using deep tillage, accomplished with equipment designed to run at depths of 30 to 40 cm, even though the effects of this practice are not well characterized. We assessed the effects of deep tillage, no tillage, and chisel plowing in the fall, with and without secondary tillage in the spring, on penetrometer resistance, plant stand, and yield of corn and soybean grown in rotation. In the spring, averaged across two years and six ... |
5. Detecting Spatially Variable Corn Nitrogen Needs Using Green Reflectance from 35MM PhotographsRising fertilizer costs and environmental concerns are reasons producers are looking to decrease nitrogen (N) fertilizer rates. This study investigated the use of relative green reflectance fiom 35 rnrn aerial photographs to detect spatially variable corn [Zea mays L.] N needs for developing variable rate fertilizer maps. Photographs were taken at three different growth stages (V7, V11, R3) at altitudes from 3,000 to 5,500 fi for two Missouri fields representing alluvial and deep loess soil type... |
6. Do Phosphorus TMDLs Interfere with Crop Nutrient RecommendationsHistorically, phosphorus (P) fertilizer recommendations for crops have been based on the crop grown, soil P test levels, locally correlated and calibrated yield responses, efficient use of P fertilizer, and fertilizer and crop price ratios. With the implementation of TMDLs and the need for reduced P loading in surface waters, P fertilizer applications must also safeguard water quality. In order to understand the challenges that this presents and the possible changes in P fertilizer recommendatio... |
7. Effect of Changing the Rotation Sequence in a Long Term Tillage and Fertility StudyA continuous experiment was conducted fiom 1970 to 1999 to determine the long term effects of fertilizer application and tillage practices on soil acidity, organic matter and nutrient changes, and crop responses. Four tillage treatments were evaluated: continuous conventional: alternate till (two years no-till: one year conventional); continuous chisel till; and continuous no-till. Five fertilizer treatments were also evaluated (Ib ac-' N-P205-K20): check, 0-0-0; 175-0-0 broadcast; 160-0-0 broad... |
8. Enhancing Soil Nitrogen Availability in Corn-Based Cropping SystemsThe development of sustainable N management systems requires a better understanding of the contribution of on-farm resources to the active N pool size and its mineralization. This study explores the effect of substrate diversity and living corn roots on improving N supply through mineralization. A "diverse system", consisting of a corn (Zea mays L.)-corn-soybean (Glycine mar L.)-wheat (Triticum aesiiwrm L.) rotation with cover crops and fertilized with composted manure was compared with a corn m... |
9. Evaluation of Banded Fertilizer for Soybean ProductionResponse of the soybean crop to phosphate and potash fertilizer when soil test levels indicate the need for additional P andlor K is well documented. The value of the additional bushels exceeds the cost of the fertilizer. In general, phosphate and potash fertilizer, when needed, can either be broadcast and incorporated before planting or applied in a band at the time of planting. The banded application is Frequently preferred for a variety of reasons. This is especially true when the soybean cro... |
10. Evaluation of Starter Fertilizer Formulations and Placements for Conservation Tillage Production SystemsWith the interest in and importance of the use of starter fertilizers in conservation tillage production systems, research was continued to evaluate higher rates of N in starter fertilizers and different starter fertilizer placements. The use of starter fertilizer containing N, P and K significantly increased corn yields compared to a N only program, even though soil P and K levels were high. Increasing N rates in direct seed placed starter did not increase yields and significantly reduced plant... |