Effects of nitrogen application stages on photosynthetic characteristics of summer maize in high yield conditions

Improvement in fertilization methods, including the optimal matching of nutrient supply and root nutrient absorption by applying nitrogen (N) in the root zone of crop, is necessary to improve N use efficiency (NUE), maintain high stable yield cultivation of maize, and contribute toward future environmental protection. The current practice of split surface broadcasting (SSB) of N is labor-intensive and the surface broadcasting causes a large amount of N to leach into the environment, yet it does not substantially increase maize yield. Root zone fertilization (RZF) has been identified as an efficient way to solve such problems. However, information on the appropriate amount of N fertilizer under RZF for summer maize remains limited. Therefore, in this study, a two-year consecutive field experiment was conducted during 2015–2016 in Anhui province, China, to investigate the effect of N rate and application method on grain yield, nutrient uptake, and NUE of summer maize. The method chosen is not only important to increase grain yield but also critical for reducing N rate and potential loss in the maize cropping system. The experiment comprised six N rates (90, 135, 180, 225, 270, and 360 kg N hm−2) and two N application methods in both 2015 and 2016. The two N application methods included SSB and one-time RZF. Results showed that grain yield of summer maize increased first and then decreased with the increase of N rate; however, when the N rate increased to 270 kg hm−2, the grain yield increased slowly or even decreased. Compared with SSB, RZF increased grain yield by 4%, and the effect of N on grain yield was mainly related to the number of kernels per ear and 1000-seed weight. One-time RZF increased N apparent recovery efficiency by 18% (7.2 percentage points) compared with SSB and also improved the N agronomic efficiency, N physiological efficiency, and N partial factor productivity. In the comprehensive consideration of yield target, NUE, and soil N balance, the optimal N rate for summer maize in the vertisol soil of Anhui province was 180–225 kg hm−2 for one-time RZF, which reduced N fertilizer by 14% compared with the SSB. Overall, one-time RZF has great potential for green and sustainable agriculture, and thus fertilization machines are worthy of development and application in maize cropping systems.

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The association of dry-matter yield with nitrogen and soluble-carbohydrate concentration in perennial ryegrass (Lolium perenne L.)

The Journal of Agricultural Science ◽

10.1017/s0021859600039071 ◽

1979 ◽

Vol 93 (3) ◽

pp. 657-667 ◽

Cited By ~ 6

Author(s):

J. Valentine ◽

A. H. Charles

Keyword(s):

Nitrogen Concentration ◽

High Yield ◽

Soluble Carbohydrate ◽

Nitrogen Application ◽

Simple Correlation ◽

Nitrogen Levels ◽

Carbohydrate Concentration ◽

Growth Room ◽

Selection For ◽

Low Nitrogen

SUMMARYThe associations between yield, nitrogen and soluble-carbohydrate concentration within S. 23 perennial ryegrass were investigated at three levels of nitrogen application. Controlled growth room conditions were used.The simple correlation between yield and nitrogen concentration was negative at the low rate of nitrogen application, not present at the intermediate rate of nitrogen and positive though not significant at the high rate of nitrogen. Yield and soluble-carbohydrate concentration were only correlated (positively) at the low nitrogen rate.At low nitrogen there were ‘efficient’ genotypes with relatively high yield and low nitrogen concentration. ‘Inefficient’ genotypes had relatively low yields and high nitrogen concentration. The majority of genotypes were neither markedly efficient or inefficient. The efficient genotypes at low nitrogen maintained their yield advantage at higher nitrogen levels with average nitrogen concentration and high numbers of tillers. Inefficient genotypes remained relatively stable in yield, numbers of tillers and nitrogen concentration.Partial correlation indicated an underlying high degree of dependence between yield, nitrogen and soluble-carbohydrate concentration at all nitrogen levels. The association of yield and nitrogen concentration showed a similar trend over nitrogen levels to that obtained using simple correlation. Yield and soluble-carbohydrate concentration were positively related, and nitrogen and soluble-carbohydrate concentration inversely related, when the effects of the remaining attribute were eliminated.Data extracted from Lee et al. (1977) confirmed that yield and nitrogen concentration for varieties under field conditions varied with level of nitrogen application in a similar manner to genotypes in the controlled growth room. The variety (Melle) could be characterized as being particularly efficient.Both sets of results indicate that selection for high yield of nitrogen in herbage can best be achieved through selection for yield alone.

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Irrigation Schedule of Greenhouse Tomato Using Pan Evaporation and Tensiometer and Effects on Yield and Soil Nitrate

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.864-867.2498 ◽

2013 ◽

Vol 864-867 ◽

pp. 2498-2502

Author(s):

Hua He ◽

Jun Liang Li

Keyword(s):

Irrigation Schedule ◽

High Yield ◽

Yield Reduction ◽

Vegetable Production ◽

Soil Nitrate ◽

Pan Evaporation ◽

Nitrogen Application ◽

Limiting Nutrient ◽

Greenhouse Vegetable ◽

Nitrate Leaching Loss

Over-application of nitrogen is widespread in greenhouse vegetable production in China and induces environmental problems. The nitrogen leaching lose from unsuitable irrigation has proved to be the bottleneck of reducing nitrogen application, and timely and adequate irrigation so became one of the key countermeasures for reduction of nitrogen application. This experiment was conducted to schedule irrigation with tensiometers and pan evaporation, probing the effects of that on tomato (Lycopersicon esculentumMill) fruit yield and soil nitrate. The results show that i) when Kcp=1.2, tomato obtain high yield while Kcp=0.4 or 0.8, the corresponding irrigation cannot meet plant need for water and lead to yield reduction, and ii) comparing with conventional irrigation, pan-evaporation-based irrigation schedules significantly reduce the amount of irrigation water to deeper soil layers, thereby limiting nutrient in soil solution downward, which results in much lower NO3-N content in subsoil and greatly mitigate the risk of nitrate leaching loss.

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