scholarly journals Effects of water salinity and N application rate on water- and N-use efficiency of cotton under drip irrigation

2013 ◽  
Vol 6 (4) ◽  
pp. 454-467 ◽  
Author(s):  
Wei Min ◽  
ZhenAn Hou ◽  
LiJuan Ma ◽  
Wen Zhang ◽  
SiBo Ru ◽  
...  
2009 ◽  
Vol 45 (3) ◽  
pp. 275-286 ◽  
Author(s):  
LIMEI ZHAO ◽  
LIANGHUAN WU ◽  
YONGSHAN LI ◽  
XINGHUA LU ◽  
DEFENG ZHU ◽  
...  

SUMMARYField experiments were conducted in 2005 and 2006 to investigate the impacts of alternative rice cultivation systems on grain yield, water productivity, N uptake and N use efficiency (ANUE, agronomic N use efficiency; PFP, partial factor productivity of applied N). The trials compared the practices used with the system of rice intensification (SRI) and traditional flooding (TF). The effects of different N application rates (0, 80, 160 and 240 kg ha−1) and of N rates interacting with the cultivation system were also evaluated. Resulting grain yields with SRI ranged from 5.6 to 7.3 t ha−1, and from 4.1 to 6.4 t ha−1 under TF management. On average, grain yields under SRI were 21% higher in 2005 and 22% higher in 2006 than with TF. Compared with TF, SRI plots had higher harvest index across four fertilizer N rates in both years. However, there was no significance difference in above-ground biomass between two cultivation systems in either year. ANUE was increased significantly under SRI at 80 kg N ha−1 compared with TF, while at higher N application rates, ANUE with SRI was significantly lower than TF. Compared with TF, PFP under SRI was higher across all four N rates in both years, although the difference at 240 kg N ha−1 was not significant. As N rate increased, the ANUE and PFP under both SRI and TF significantly decreased. Reduction in irrigation water use with SRI was 40% in 2005 and 47% in 2006, and water use efficiency, both total and from irrigation, were significantly increased compared to TF. With both SRI and TF, the highest N application was associated with decreases in grain yield, N use efficiency and water use efficiency. This is an important finding given current debates whether N application rates in China are above the optimum, especially considering consequences for soil and water resources. Cultivation system, N rates and their interactions all produced significant differences in this study. Results confirmed that optimizing fertilizer N application rates under SRI is important to increase yield, N use efficiency and water use efficiency.


2016 ◽  
Vol 55 (2) ◽  
pp. 136-144 ◽  
Author(s):  
R. Hackett

Abstract A range of cultivar types, including two-row and six-row types as well as line and hybrid types, are used for winter barley production in Ireland. There is little information available on the fertiliser nitrogen (N) requirements or the N use efficiency of these different types, particularly under Irish conditions. The objectives of the work presented here were to compare the response to fertiliser N of a two-row line cultivar, a six-row line cultivar and a six-row hybrid cultivar in terms of grain yield and aspects of N use efficiency. Experiments were carried out over three growing seasons, in the period 2012-2014, on a light-textured soil comparing the response of the three cultivars of winter barley to fertiliser N application rates ranging from 0 to 260 kg N/ha. There was no evidence that cultivar type, regardless of whether it was a two-row or six-row line cultivar or a six-row hybrid cultivar, influenced the response to fertiliser N of winter barley. There were some indications that six-row cultivars were less efficient at recovering soil N but used accumulated N more efficiently than the two-row cultivar. This work provided no evidence to support adjustment of fertiliser N inputs to winter barley based on cultivar type.


HortScience ◽  
2013 ◽  
Vol 48 (4) ◽  
pp. 485-492 ◽  
Author(s):  
Desire Djidonou ◽  
Xin Zhao ◽  
Eric H. Simonne ◽  
Karen E. Koch ◽  
John E. Erickson

In addition to managing soilborne diseases, grafting with vigorous rootstocks has been shown to improve yield in tomato (Solanum lycopersicum L.) production. However, the influence of different levels of nitrogen (N) and irrigation supplies on grafted tomato plants has not been fully examined in comparison with non-grafted plants, especially under field conditions. The objective of this two-year study was to determine the effects of different irrigation regimes and N rates on yield, irrigation water use efficiency (iWUE), and N use efficiency (NUE) of grafted tomato plants grown with drip irrigation in sandy soils of north Florida. The determinate tomato cultivar Florida 47 was grafted onto two interspecific hybrid rootstocks, ‘Beaufort’ and ‘Multifort’ (S. lycopersicum × S. habrochaites S. Knapp & D.M. Spooner). Non-grafted ‘Florida 47’ was used as a control. Plants were grown in a fumigated field under 12 combinations of two drip irrigation regimes (50% and 100% of commonly used irrigation regime) and six N rates (56, 112, 168, 224, 280, and 336 kg·ha−1). The field experiments were arranged in a split-plot design with four replications. The whole plots consisted of the irrigation regime and N rate combination treatments, whereas the subplots represented the two grafting treatments and the non-grafted plants. Self-grafted ‘Florida 47’ was also included in the 100% irrigation and 224 kg N/ha fertilization treatment as a control. In 2010, the 50% irrigation regime resulted in higher total and marketable yields than the 100% irrigation regime. Tomato yield was significantly influenced by N rates, but similar yields were achieved at 168 kg·ha−1 and above. Plants grafted onto ‘Beaufort’ and ‘Multifort’ showed an average increase of 27% and 30% in total and marketable fruit yields, respectively, relative to non-grafted plants. In 2011, fruit yields were affected by a significant irrigation by N rate interaction. Grafting significantly increased tomato yields, whereas grafted plants showed greater potential for yield improvement with increasing N rates compared with non-grafted plants. Self-grafting did not affect tomato yields. More fruit per plant and higher average fruit weight as a result of grafting were observed in both years. Grafting with the two rootstocks significantly improved the irrigation water and N use efficiency in tomato production. Results from this study suggested the need for developing irrigation and N fertilization recommendations for grafted tomato production in sandy soils.


2019 ◽  
Vol 56 (Special Issue) ◽  
pp. 125-135
Author(s):  
D Panda ◽  
AK Nayak ◽  
S Mohanty

Nitrogen is the one of most limiting nutrient for rice production, and in India rice cultivation alone accounts approximately 37% of the total fertilizer-N consumption in the year 1917-18. However, 60-70% of applied N is lost from the rice ecosystem system in the form of reactive N species such as ammonia (NH3), nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2) and nitrate (NO3) through various processes. Hence enhancing N use efficiency through improved N management is of greater importance for ensuring food security and environmental sustainability. The decisions on optimum level, time, form and method of N application are crucial to an efficient N management strategy. Earlier studies suggested blanket fertilizer recommendations for different rice ecosystems and soil test based fertilizer applications. Subsequently, innovative methods of N application including deep placement of urea super granule in reduced zone, subsurface incorporation of urea through farmer friendly methods were also recommended Recently several advancements have been made in N management practices for rice crop such as site specific N management, real time N management using leaf colour chart (LCC) and customised LCC, enhanced efficiency N fertilizers (EENF) using N transformation regulators and GIS and remote sensing (RS) - based N application technologies. The objective of this paper is to comprehensively discuss about the established and emerging N management options for improving yield, N use efficiency and environmental sustainability of rice.


Soil Research ◽  
2004 ◽  
Vol 42 (7) ◽  
pp. 727 ◽  
Author(s):  
S. K. Dong ◽  
Y. Jiang ◽  
M. J. Wei ◽  
R. J. Long ◽  
Z. Z. Hu ◽  
...  

To illustrate the effect of nitrogen (N) application on soil physical and chemical characteristics, herbage yield and quality, and nitrogen and water use efficiency in the alpine region of Qinghai-Tibetan Plateau, a 3-year experiment was conducted on 3 mixtures of 4 perennial grasses commonly cultivated on the Plateau, Bromus inermis (BI) + Elymus nutans (EN), BI + E. sibricus (ES) + Agropyron cristatum (AC), and BI + ES + EN + AC by applying 4 levels of N fertiliser, 0, 115, 230, and 345 kg/ha from 1998 to 2000 in a randomised design. At harvesting time, soil pH and soil dry bulk density at 0–30 cm depth did not vary with N application rate. Soil organic carbon at 0–30 cm was not significantly variable under different N rates. Total soil N at 0–30 cm increased with N application rate and application year. After 3 years’ consecutive N treatment, total soil N reached 13 g/kg at an N application rate of 345 kg/ha. Soluble soil N at 0–30 cm increased with application rate but decreased with application year. At 345 kg N/ha application rate, soluble soil N was >100 mg/kg in 1998, but decreased to around 80 mg/kg in 2000. Herbage DM yields increased linearly with the N application rate. Compared with no fertiliser, 1.5 times more DM yield in 1998 and nearly double the DM yield in 1999 and 2000 were harvested for all grass mixtures at 345 kg N/ha. N concentrations in the herbages were significantly improved by N application. Each N fertiliser rate increased N contents in grass herbages by ≈3 g organic matter/kg. Apparent nitrogen recovery (ANR) decreased with N application rate in the establishment year of 1998, but increased with N application rate in 1999 and 2000. N use efficiency (NUE) decreased with N application throughout the experiment. Precipitation use efficiency (PUE) was significantly improved by N application for each grass mixture. Positive residual N-fertiliser effects were observed on herbage DM yield, ANR, NUE, and PUE in this study. BI + ES + AC showed higher DM yields, ANR, NUE, and PUE than the other 2 grass mixtures, and thus was proposed for N-input grassland systems in the alpine region of the Qinghai-Tibetan Plateau.


2019 ◽  
Vol 56 (Special) ◽  
pp. 125-135
Author(s):  
D Panda ◽  
AK Nayak ◽  
S Mohanty

Nitrogen is the one of most limiting nutrient for rice production, and in India rice cultivation alone accounts approximately 37% of the total fertilizer-N consumption in the year 1917-18. However, 60-70% of applied N is lost from the rice ecosystem system in the form of reactive N species such as ammonia (NH3), nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2) and nitrate (NO3) through various processes. Hence enhancing N use efficiency through improved N management is of greater importance for ensuring food security and environmental sustainability. The decisions on optimum level, time, form and method of N application are crucial to an efficient N management strategy. Earlier studies suggested blanket fertilizer recommendations for different rice ecosystems and soil test based fertilizer applications. Subsequently, innovative methods of N application including deep placement of urea super granule in reduced zone, subsurface incorporation of urea through farmer friendly methods were also recommended Recently several advancements have been made in N management practices for rice crop such as site specific N management, real time N management using leaf colour chart (LCC) and customised LCC, enhanced efficiency N fertilizers (EENF) using N transformation regulators and GIS and remote sensing (RS) - based N application technologies. The objective of this paper is to comprehensively discuss about the established and emerging N management options for improving yield, N use efficiency and environmental sustainability of rice.


HortScience ◽  
1990 ◽  
Vol 25 (10) ◽  
pp. 1293-1296 ◽  
Author(s):  
C.M. Tankou ◽  
B. Schaffer ◽  
S.K. O'Hair ◽  
C.A. Sanchez

The effects of applied N and shading duration on net gas exchange and growth of two southern Florida cassava (Manihot esculenta Crantz.) cultivars grown in containers were determined. Both cultivars responded similarly to shading and N with respect to the measured variables. There were no interactions between shading duration and N application rate for any of the variables measured. Tissue dry weights, total leaf N and chlorophyll concentrations, net CO2 assimilation (A), transpiration (E), water-use efficiency (WUE), and stomatal conductance (gs) were quadratically related to the concentration of N applied to the soil. The optimum N application rate for maximum growth of both cultivars was 60 mg/plant per day. Increased shading duration reduced A, E, gs, WUE, storage root number, and weight and increased the shoot : root ratio.


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