scholarly journals Can Long-Term Experiments Predict Real Field N and P Balance and System Sustainability? Results from Maize, Winter Wheat, and Soybean Trials Using Mineral and Organic Fertilisers

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1472
Author(s):  
Ilaria Piccoli ◽  
Felice Sartori ◽  
Riccardo Polese ◽  
Maurizio Borin ◽  
Antonio Berti

Agri-environmental indicators such as nutrient balance may play a key role in soil and water quality monitoring, although short-term experiments might be unable to capture the sustainability of cropping systems. Therefore, the objectives of this study are: (i) to evaluate the reliability of long-term experimental N and P balance estimates to predict real field (RF) (i.e., short-term transitory) conditions; and (ii) to compare the sustainability of short- and long-term experiments. The LTE-based predictions showed that crops are generally over-fertilised in RF conditions, particularly maize. Nutrient balance predictions based on the LTE data tended to be more optimistic than those observed under RF conditions, which are often characterised by lower outputs; in particular, 13, 44, and 47% lower yields were observed for winter wheat, maize, and soybean, respectively, under organic management. The graphical evaluation of N and P use efficiency demonstrated the benefit of adopting crop rotation practices and the risk of nutrient loss when liquid organic fertiliser was applied on a long-term basis. In conclusion, LTE predictions may depend upon specific RF conditions, representing potential N and P use efficiencies that, in RF, may be reduced by crop yield-limiting factors and the specific implemented crop sequence.

2009 ◽  
Vol 323 (1-2) ◽  
pp. 143-151 ◽  
Author(s):  
Xu Tang ◽  
Yibing Ma ◽  
Xiying Hao ◽  
Xiuying Li ◽  
Jumei Li ◽  
...  

1970 ◽  
Vol 74 (2) ◽  
pp. 397-407 ◽  
Author(s):  
J. S. Brockman ◽  
P. G. Shaw ◽  
K. M. Wolton

SUMMARYAn experiment was carried out over a 5-year period on a grass/clover sward at North Wyke to compare three methods of experimental management—individually grazed plots, communally grazed plots and cutting with removal of herbage. Responses to phosphate and potash fertilizers under each management were measured.P fertilizer increased grass yields in the first 4 years and decreased clover yields in the last 2. In almost all respects cut and grazed sward responded similarly to P. Fertilizer K had no effect on grass yield but markedly increased clover yield and raised herbage K content. Grazed swards developed a higher herbage K content than cut swards, and K fertilizer increased it more in the fourth and fifth years on the individually grazed than on the communally grazed plots. Thus communal grazing resulted in appreciable transfer of K from plot to plot in animal returns.It is concluded that whilst cutting management may be used for short-term experiments, its use in long-term experiments gives different results from grazing. Communal grazing can lead to the transfer of N and K effects from plot to plot, so that plots must be grazed individually except perhaps where P is the only variable nutrient.


1960 ◽  
Vol 54 (1) ◽  
pp. 131-139 ◽  
Author(s):  
N. K. Jenkins ◽  
C. Tyler

A long-term calcium and phosphorus balance experiment with laying hens is described.The cumulative balances of calcium and phosphorus over a whole year were seen to be physiologically impossible.Results from other workers using short term balances could be equally impossible and a similar situation has recently been noted in balance experiments with ruminants.The techniques employed in the experiment were, therefore, investigated in detail.Only systematic errors could be responsible and it was found that the most likely source of such errors was (a) the spilling of food on to the floor or into the water bowl, and (b) failure to collect all the droppings.These errors only become apparent in long-term experiments and are more pronounced when diets containing high levels of calcium and/or phosphorus are fed.


2021 ◽  
pp. M58-2021-5
Author(s):  
Tim Burt ◽  
Gilles Pinay ◽  
Fred Worrall ◽  
Nicholas Howden

AbstractThis chapter reviews research on solutes by fluvial geomorphologists in the period 1965 to 2000; growing links with biogeochemical research are emphasised later in the chapter. Brief reference is necessarily made to some research from before and after the study period. In relation to solutes, early research sought to relate short-term process observations to long-term landform evolution. However, very quickly, research moved into much more applied fields, less concerned with landforms and more with biogeochemical processes. The drainage basin became the focus of research with a wide range of interest including nutrient loss from agricultural and forested landscapes to dissolved organic carbon export from peatlands. In particular, the terrestrial-aquatic ecotone became a focus for research, emphasising the distinctive processes operating in the riparian zone and their contribution to river water protection from land-derived pollutants. By the end of the period, the scale and range of fluvial geomorphology had been greatly transformed from what it had been in 1965, providing a distinctive contribution to the broader field of biogeochemistry as well as an ongoing contribution to the study of Earth surface processes and landforms.


1985 ◽  
Vol 107 (3) ◽  
pp. R9-R12 ◽  
Author(s):  
A. T. Holder ◽  
R. Aston ◽  
M.A. Preece ◽  
J. Ivanyi

ABSTRACT This work demonstrates that complexing hGH with monoclonal antibody EBl (MAB-EBl) can produce a striking potentiation of the somatogenic actions of hGH in vivo in Snell dwarf mice. In short-term experiments significant increases in cartilage metabolism and body weight were noted; these responses were dose-dependent for both MAB-EBl and hGH concentration. Increased growth was also observed in long-term experiments. In marmosets where MAB-EBl cross-reacts with endogenous GH, MAB-EBl alone enhanced the actions of endogenous GH. A new perspective may be necessary to incorporate these results into the current concept of antibody action.


2018 ◽  
pp. 357-369
Author(s):  
Péter Pepó

The impact of agrotechnical management practices (nutrient and water supply, crop rotation, crop protection, genotype) on the yields of winter wheat and maize and on the soil water and nutrient cycles was studied in long-term experiments set up in 1983 in Eastern Hungary on chernozem soil. The long-term experiments have shown that nitrogen fertilizer rates exceeding the N-optimum of winter wheat resulted in the accumulation of NO3-N in the soil. Winter wheat varieties can be classified into four groups based on their natural nutrient utilization and their fertilizer response. The fertilizer responses of wheat varieties depended on crop year (6.5–8.9 t ha-1 maximum yields in 2011–2015 years) and the genotypes (in 2012 the difference was ~3 t ha-1 among varieties). The optimum N(+PK) doses varied between 30–150 kg ha-1 in different crop years. In maize production fertilization, irrigation and crop rotation have decision role on the yields. The efficiency of fertilization modified by cropyear (in dry 891–1315 kg ha-1, in average 1927–4042 kg ha-1, in rainy cropyear 2051–4473 kg ha-1 yield surpluses of maize, respectively) and crop rotation (in monoculture 1315–4473 kg ha-1, in biculture 924–2727 kg ha-1 and triculture 891–2291 kg ha-1 yield surpluses of maize, respectively). The optimum fertilization could improve the water use efficiency in maize production. Our long-term experiments gave important ecological and agronomic information to guide regional development of sustainable cropping systems.


2015 ◽  
Author(s):  
Toshiro Yamada ◽  
Yasuhiro Yamada ◽  
Kazuko Yamada

Neonicotinoides are persistent and highly toxic pesticides that have become popular instead of organophosphates, being suspected to be a trigger of massive disappearance of bees that raises concern in the world. The evaluation of the long-term influence for a whole colony in the natural environment is, however, not established yet. In this paper, we conducted a long-term field experiment and found different impacts on honeybee colonies (Apis mellifera) in an apiary between the neonicotinoid dinotefuran and the organophosphate fenitrothion even though whose concentrations in sugar syrup provided for bees were adjusted to have nearly equal short-term effects on a honeybee based on the median lethal dose (LD50) as well as the insecticidal activity to exterminate stinkbugs. The colony with administration of dinotefran (dinotefuran colony) became extinct in 26 days, while the colony with administration of fenitrothion (fenitrothion colony) survived the administration for the same period. Furthermore, the fenitrothion colony succeeded to be alive for more than 293 days after administration, and also succeeded an overwintering, which indicates that colonies exposed to fenitrothion can recover after the exposure. Meanwhile, the dinotefuran colony became extinct even though the intake of dinotefuran was estimated to be comparable with that of fenitrothion in terms of the LD50 of a honeybee. Moreover, the colonies in our previous long-term experiments where dinotefuran with higher concentration were administered only for first few days (Yamada et al., 2012) became extinct in 104 days and 162 days, respectively. From these results, we speculate that colonies exposed to dinotefuran hardly recover from the damage because dinotefuran is much more persistent than fenitrothion and toxic foods stored in cells can affect a colony in a long period.


2018 ◽  
Vol 8 (3) ◽  
pp. 193
Author(s):  
Gordon Foli ◽  
George Obeng ◽  
Michael Adjaloo ◽  
Donald Amrago ◽  
Ebenezer Mensah

This paper uses risk assessment of socio-economic and environmental indicators to develop criteria for apportionment (AP) of funds to communities impacted by mining activities within a Forest Reserve environment in Ghana. A t-test statistic of assessment data shows that factors such as; cost of living, health conditions, air pollution, water contamination, land degradation and distance (D km) are significant. Ratings of the factors using a 1-5 intensity scale to determine risk values (RV) for communities indicate that RV of 25 requires no remediation, while (25-RV) is remediation factor. A long-term AP criterion using the ranked risk (RR) values is defined by the equation APRR%=7.45-0.233(RR) with R2 of 0.961. Based on this criterion, communities D and S which are located at 1.5 and 16.1km from the mining focus have APRR values of 7.23% and 2.26%, respectively. APRR% in relation to distance is defined by the equation APRR%=7.22-0.281(D) with R2 of 0.647. RR-dependent distance equation (APD %) is used to deduce a short-term criterion defined by K*APD%=4.13-0.097(RR), where K is a constant. The expression of (APRR-K*APD) represents the residual apportionment required after a long-term assessment. The findings in this research demonstrate well-defined patterns that can be replicated for similar future projects.


2019 ◽  
Vol 24 (10) ◽  
pp. 2285-2289
Author(s):  
XIAOYING WEI ◽  
ZHI-QIANG ZHANG

Predators can influence prey directly by consuming them, or indirectly by inducing stress to them. In previous studies, the exposure of leaves or containers to predators is short term and the replacement of such predator-exposed units for any long-term experiments is laborious. This study aims to establish a new method to enable continuous predator-induced stress to prey by using a modified Munger cell, with Tyrophagus putrescentiae and its predator predator Neoseiulus cucumeris as an example.


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