Enhanced Efficiency Liquid Nitrogen Fertilizer Management for Corn Production

Table 5

Chlorophyll meter readings, plant population, grain yield, moisture, protein, and oil concentration response to nitrogen sources/placements at 168 kg·N·ha⁻¹. Data were combined over factors or years in the absence of a significant interaction. Surface treatments were no-tillage with surface applied nitrogen and deep treatments were strip tillage with deep banded nitrogen application.

N source placement	Chlorophyll meter readings			Corn plant population		Corn grain parameters
						Yield						Moisture	Protein			Oil
	2011	2012	2013			2011		2012		2013			2011	2012	2013
				F	S	F	S	F	S	F	S
	SPAD units			No. ha^−1		Mg·ha^−1							g·kg^−1
Surface UAN^†	55.6	52.8	45.9	71,100	70,300	8.94	8.11	1.41	1.75	8.08	8.16	181b	77.8	103.8	75.9	32.7
Deep UAN	57.3	56.9	50.7	66,700	57,000	9.12	5.52	1.27	1.35	8.46	8.60	190b	92.5	104.5	88.4	31.1
Surface NF	50.7	53.6	48.8	73,050	70,450	8.56	7.38	1.63	1.79	8.01	8.68	175b	77.5	103.9	84.4	31.4
Deep NF	56.2	55.6	44.7	69,900	54,250	8.47	6.06	1.30	1.78	8.42	8.36	207a	93.8	104.8	83.1	32.6
Deep AA	55.9	55.4	43.8	64,000	58,650	9.06	6.36	1.44	1.71	6.80	8.50	215a	92.0	104.3	79.9	33.1
LSD ()^‡	5.2			9,800		1.03						16	6.9			1.3

^†Abbreviations: AA, anhydrous ammonia; F, fall; NF, Nitamin Nfusion; S, spring; UAN, 32% urea ammonium nitrate. ^‡Fisher’s protected least significant difference at .