Cornstalk Testing to Evaluate Nitrogen Management

Blackmer, A. M.; Mallarino, Antonio P.

doi:10.31274/icm-180809-730

Cited by 57 publications

(112 citation statements)

References 0 publications

Supporting

Mentioning

107

Contrasting

Unclassified

Order By: Relevance

“…The correlation of SPAD readings at V8 and R2 with grain yield was highly significant across N systems (r > 0.42; P < 0.001). Stalk NO 3 -N was linearly increasing with no maximum; N rate was then predicted by the linear model to produce the sufficiency level of 2000 mg kg −1 (Blackmer and Mallarino, 1996). Nitrogen rates that produced stalk NO 3 -N concentration of 2000 mg kg −1 were much lower than those that maximized grain yield, which is probably attributed to the starter N and irrigation water NO 3 -N at this site.…”

Section: Nitrogen Indicators and Grain Yieldmentioning

confidence: 99%

“…Ten 0.2-m-long stalk samples were taken at the base of the plant starting 0.15 m above the ground. These samples were taken outside the harvest area from each plot, air dried, and analyzed for NO 3 -N (Blackmer and Mallarino, 1996). For total dry matter production, six plants were randomly cut at ground level within 1 wk after the R6 stage.…”

Section: Field and Plant Measurementsmentioning

confidence: 99%

See 1 more Smart Citation

Use of Five Nitrogen Source and Placement Systems for Improved Nitrogen Management of Irrigated Corn

Shapiro

Attia

Ulloa

et al. 2016

Soil Science Soc of Amer J

View full text Add to dashboard Cite

Section: Nitrogen Indicators and Grain Yieldmentioning

confidence: 99%

Section: Field and Plant Measurementsmentioning

confidence: 99%

Use of Five Nitrogen Source and Placement Systems for Improved Nitrogen Management of Irrigated Corn

Shapiro

Attia

Ulloa

et al. 2016

Soil Science Soc of Amer J

View full text Add to dashboard Cite

“…Ten 20 cm (8 in) stalk segments (15 cm [6 in] above the ground) were cut within each sampling area (Blackmer and Mallarino 1996) that included two corn rows extending for about 10 to 12 m (33 to 40 ft). The collected samples were analyzed for stalk nitrate nitrogen concentrations with a Lachat flow-injection analyzer (Lachat Instruments, Milwaukee, Wisconsin).…”

Section: Methodsmentioning

confidence: 99%

Late-season digital aerial imagery and stalk nitrate testing to estimate the percentage of areas with different nitrogen status within fields

Kyveryga¹,

Blackmer²,

Pearson³

et al. 2011

Journal of Soil and Water Conservation

View full text Add to dashboard Cite

Farmers are rapidly adopting various precision agriculture technologies (PAT), such as yield monitoring, variable-rate fertilizer applications, and remote sensing tools (Griffin et al. 2008). Spatial and temporal variability in soil properties, plant characteristics, and crop yields can be used Abstract: Precision agriculture technologies offer potential economic and environmental benefits from site-specific management of nitrogen (N) fertilizer and animal manure sources for corn (Zea mays L.). However, lack of knowledge and reliable methodology for developing and evaluating site-specific N fertilizer recommendations are the major obstacles for realizing these potential benefits. The objective of this study was to evaluate corn N status at the field scale and across many fields using late-season digital aerial imagery and the end-of-season corn stalk nitrate test in large-scale on-farm evaluation studies. About 30 groups of farmers, lead by agronomists and crop consultants, were formed across Iowa to evaluate different N management practices. Late-season color digital aerial imagery and digital soil maps were used to guide the collection of the corn stalk nitrate test samples within 683 cornfields in 2006, 824 fields in 2007, and 828 fields in 2008. Four areas-one from each of the three predominant soil types and one within a target-deficient area-were sampled in each field. Multilevel binary logistic regressions were used to quantify the relationship between green reflectance of the corn canopy and corn N status, expressed as deficient and sufficient (a combination of marginal, optimal, and excessive categories of the corn stalk nitrate test), within and across the fields. Percentages of areas within fields with deficient and sufficient N status were estimated using distributions of pixel counts of green reflectance of the corn canopy. Multiple regression analysis was used to identify factors affecting percentage-deficient area within the fields. Results showed that N management category (a combination of N form and timing of application) and early season rainfall (May, June, or cumulative from March through June) had the largest effects on percentage-deficient area. Fields with liquid swine manure applied in the fall or urea-ammonium nitrate solution applied in the spring (before planting) or urea-ammonium nitrate solution applied at sidedress had larger areas of N deficiency than fields with anhydrous ammonia applied in the spring. Larger early season rainfalls also increased percentage-deficient area during each year. The results of large-scale evaluations can be used to develop more accurate site-specific N recommendations based on knowledge of differences between management practices and effects of soil properties and rainfall on N status within fields. Future evaluations can identify areas that persistently have excessive N status and quantify potential N fertilizer reductions within those areas or fields.Key words: adaptive management-corn stalk nitrate test-digital aerial imagery-nitrogen management-pre...

show abstract

“…In 2010, BSN was greater in WS than FI for two systems (split-U at 180 kg N ha -1 and IU at 180 kg N ha -1 ) but did not differ Asterisks (*) indicate significant differences between FI and WS at Pc < c0.05 for a given N rate. In (b), colored horizontal lines represent boundaries between excessive, optimal, marginal, and low BSN categories (Blackmer and Mallarino, 1996).…”

Section: Source/timing/rate Studymentioning

confidence: 99%

“…Samples were dried to constant weight at 65°C, ground using a Wiley mill and then extracted with water for subsequent BSN determination (Carlson et al, 1990). The BSN results were categorized into excessive, optimal, marginal, and low ranges as defined by Blackmer and Mallarino (1996). Relative N use efficiency was expressed as N fertilizer recovery efficiency (NFRE, %), calculated using (B f -B 0 )/F×100, where B is ANU (kg N ha -1 ), F is fertilizer N applied (kg N ha -1 ) and the subscripts f and 0 refer to values for a given treatment and the zero-N control treatment, respectively, within the same block.…”

Section: Crop Measurementsmentioning

confidence: 99%

Corn Response to Nitrogen Management under Fully‐Irrigated vs. Water‐Stressed Conditions

et al. 2016

View full text Add to dashboard Cite

Characterizing corn (Zea mays L.) grain yield (GY) response to N is critical for maximizing profits, increasing N use efficiency and minimizing environmental impacts. Although a large database of GY response to N exists for highly productive soils, few data exist for less productive soils. While changes in precipitation are expected in the future, few studies have compared GY response to varying N management practices under conditions of varying water availability. We measured GY and basal stalk nitrate nitrogen (BSN) at harvest using split‐applied urea at eight N rates under fully‐irrigated (FI) and water‐stressed (WS) conditions in a loamy sand over 2 yr (2009 and 2010). We also measured GY and BSN using single, pre‐plant applications of urea, polymer‐coated urea (PCU) and urea amended with urease and nitrification inhibitors (IU) at one or two N rates. The results showed that economic optimum nitrogen rate (EONR) and agronomic optimum nitrogen rate (AONR) did not vary by water management, in spite of significant increases in GY (up to 48%) under FI compared to WS. Modification of N fertilizer timing or N source was effective for increasing GY (by 18–41%) with FI, but did not affect GY under WS conditions. Averaged across years, BSN was greater with WS compared to FI at most N rates; however, BSN corresponding to AONR was within the optimal range for both water regimes. These findings may have important implications in areas where changes in irrigation practices or water availability are expected under future climate conditions. Better understanding of water stress effects on corn response to N is needed. We measured yield response to N management with full irrigation and under water‐stress. Optimum N rate did not vary by water management despite significant yield differences. Optimizing fertilizer timing or source increased yield but only with full irrigation. Basal stalk nitrate was higher with water‐stress than with full irrigation.

show abstract

Cornstalk Testing to Evaluate Nitrogen Management

Cited by 57 publications

References 0 publications

Use of Five Nitrogen Source and Placement Systems for Improved Nitrogen Management of Irrigated Corn

Use of Five Nitrogen Source and Placement Systems for Improved Nitrogen Management of Irrigated Corn

Late-season digital aerial imagery and stalk nitrate testing to estimate the percentage of areas with different nitrogen status within fields

Corn Response to Nitrogen Management under Fully‐Irrigated vs. Water‐Stressed Conditions

Contact Info

Product

Resources

About