Factors affecting soil acidification under legumes. II. Effect of phosphorus supply

1998 ◽  
Vol 49 (4) ◽  
pp. 657 ◽  
Author(s):  
R. Y. Fang ◽  
C. Tang ◽  
C. Raphael

Phosphorus deficiency is common in crop production. This pot experiment examined whether the supply of Ca(H2PO4)2 affected acid production by N2-fixing plants of 5 grain and 4 pasture legume species grown in a P-deficient sandy soil for 60-64 days. The legume species differed greatly in their response to P application. Lupinus albus, L. luteus, and Biserrula pelecinus were less responsive to P supply than Cicer arietinum, Vicia faba, Medicago polymorpha, Ornithopus sativus, and Trifolium subterraneum, which in turn were less reponsive than L. angustifolius. Increasing P supply up to moderately deficient levels increased the amount of acid production per unit shoot biomass (specific acid production), and further increasing P decreased specific acid production. The effect of species on acid production was greater than the effect of P supply. Among the species, C. arietinum had the highest specific acid production and B. pelecinus the lowest. Specific acid production was correlated with concentrations of excess cations and ash alkalinity as well as Ca and Mg but not P in shoot. There was a very good agreement between total acid production and total content of excess cations in the whole plant, irrespective of P supply and plant species. The results suggest that acid production by legumes under various P supplies is related to the imbalance of cation and anion uptake.

1998 ◽  
Vol 49 (1) ◽  
pp. 53 ◽  
Author(s):  
C. Tang ◽  
L. Barton ◽  
C. Raphael

The capacity of subterranean clover (Trifolium subterraneum L. cv. Clare), medic (Medicago murex Willd. cv. Zodiac), serradella (Ornithopus sativus Brot. line SP1/13), biserrula (Biserrula pelecinus L. line Mor99), and woolly clover (Trifolium tomentosum L.) to acidify soil under N2 fixation was compared in a pot experiment using a poorly buffered sandy soil. The amount of acid produced per kg shoot dry matter (specific acid production) varied betweefin species and with growth stages, ranging from 44 to 128 cmol/kg shoot. Subterranean clover and serradella acidied soil to a greater extent than woolly clover and medic, whereas biserrula acidified soil least. Irrespective of pasture species and growth stage, specific acid production correlated well with concentrations of excess cations and calcium in shoots. Furthermore, total excess cation, ash alkalinity, and calcium in shoots were all good indicators of total acid production across all of the species.


1997 ◽  
Vol 37 (5) ◽  
pp. 563 ◽  
Author(s):  
C. Tang ◽  
L. Barton ◽  
C. D. A. McLay

Summary.The use of legumes to improve the productivity of pastures has usually been associated with an increase in soil acidification. The present study compared the acidification potential of 12 N2-fixing pasture legume species/genotypes using a solution culture assay. The legumes were chosen because of their use or potential use in farming systems in the mediterranean zones of southern Australia. The species grown were Trifolium subterraneum L. (vars. Dalkeith, Yarloop and Clare), Trifolium glomeratum L., Trifolium tomentosum L., Medicago murex Willd., Medicago polymorpha L., Medicago truncatulaGaertn., Ornithopus compressus L., Ornithopus sativusBrot., Trifolium vesiculosum and Trifolium balansae. Proton excretion was measured over a period of 21 days from days 40 to 61 after germination. The amount of protons excreted into solution varied between 143 and 265 cmol H+ /kg dry matter for the different species and genotypes. In general, T. tomentosum and T. glomeratum excreted greater amounts of protons per unit biomass than Medicago species and T. subterraneum, which, in turn, excreted more protons than Ornithopus species. The amount of proton excreted per kilogram biomass was well correlated with the concentrations of excess cations over anions and ash alkalinity in plants across all the species. Total acid production was highly correlated with accumulation of excess cations and ash alkalinity, total dry matter production and total nitrogen fixation during the study period. It is suggested that the potential proton excretion by new pasture legume species should be considered when they are introduced into farming systems.


2021 ◽  
Vol 12 ◽  
Author(s):  
Sarah Tepler Drobnitch ◽  
Louise H. Comas ◽  
Nora Flynn ◽  
Jorge Ibarra Caballero ◽  
Ryan W. Barton ◽  
...  

Root pressure, also manifested as profusive sap flowing from cut stems, is a phenomenon in some species that has perplexed biologists for much of the last century. It is associated with increased crop production under drought, but its function and regulation remain largely unknown. In this study, we investigated the initiation, mechanisms, and possible adaptive function of root pressure in six genotypes of Sorghum bicolor during a drought experiment in the greenhouse. We observed that root pressure was induced in plants exposed to drought followed by re-watering but possibly inhibited by 100% re-watering in some genotypes. We found that root pressure in drought stressed and re-watered plants was associated with greater ratio of fine: coarse root length and shoot biomass production, indicating a possible role of root allocation in creating root pressure and adaptive benefit of root pressure for shoot biomass production. Using RNA-Seq, we identified gene transcripts that were up- and down-regulated in plants with root pressure expression, focusing on genes for aquaporins, membrane transporters, and ATPases that could regulate inter- and intra-cellular transport of water and ions to generate positive xylem pressure in root tissue.


2017 ◽  
Vol 35 (3) ◽  
pp. 117-127
Author(s):  
Daniel E. Wells ◽  
Jeffrey S. Beasley ◽  
Edward W. Bush ◽  
Lewis. A. Gaston

Abstract Poultry litter ash (PLA) is a byproduct of bioenergy production and an effective P source for horticultural crops since it reduces P losses from container production due to its low P solubility. Experiments were conducted to determine effects of rate and placement of PLA on P loss from greenhouse crop production and growth and quality of two commonly-grown greenhouse crops, Verbena canadensis Britton ‘Homestead Purple' and Lantana camara L. ‘New Gold', by comparing two rates (140 and 280 g·m−3 P or 0.4 and 0.8 lb·yd−3) and two application methods (post-plant topdressed and pre-plant incorporated). Leachate-dissolved reactive phosphorus (DRP) concentrations were reduced by an average of 24% as P rate was reduced from 280 to 140 g·m−3, but were 134% less on average when PLA was topdressed instead of incorporated. Foliar P concentrations were less 33% and 44% for verbena and lantana, respectively when plants were topdressed compared to incorporated. Shoot biomass of verbena and lantana was 9% and 24% greater, respectively, when incorporating instead of topdressing PLA. As a P source, PLA should be pre-plant incorporated within the substrate at a total P rate between 140 g·m−3 (0.4 lb·yd−3) and 280 g·m−3 (0.8 lb·yd−3). Index words: phosphorus, poultry litter ash, Verbena canadensis Britton ‘Homestead Purple', Lantana camara L. ‘New Gold', dissolved reactive phosphorus. Species used in this study: ‘Homestead Purple' verbena (Verbena canadensis Britton); ‘New Gold' lantana (Lantana camara L.).


1995 ◽  
Vol 75 (4) ◽  
pp. 841-849 ◽  
Author(s):  
S. Brebaum ◽  
G. J. Boland

Sweet white lupin (Lupinus albus) is an emerging crop in Ontario and, in 1993, up to 600 ha acres of lupin were planted. This crop is adapted to cool and moderately warm climates, is frost-resistant to −2 °C, requires sandy to loamy soils, requires inoculation with Bradyrhizobium sp. to achieve high yields, and improves soil structure and nutrients when included in a crop rotation. The crop requires 119–135 d to mature and is thermosensitive; both traits can reduce yield in seasons with unfavourable environments. The crop is not particularly competitive with weeds and effective weed control is a critical factor in crop production. Lupin is attacked by several pathogens and insects but knowledge on appropriate pest management practices needs to be improved. The harvested seed of sweet white lupin is primarily used as an on-farm source of protein. Seeds do not require heat treatment prior to being used as animal feed and can be included as a part of the protein component in the diets of ruminants, swine and poultry. High protein digestibility and high fibre content of lupin seeds can limit incorporation into the diets of ruminants and swine, respectively. Lupin can be beneficial in human diets because milk from lupin-fed animals contains more unsaturated fatty acids and less saturated fatty acids than milk from animals fed soybean meal. Sweet white lupin has several advantages and disadvantages as an emerging crop in Ontario, but additional research and development are needed. Key words: Lupin (sweet white), Lupinus albus


2002 ◽  
Vol 82 (2) ◽  
pp. 273-282 ◽  
Author(s):  
J. T. McConnell ◽  
P. R. Miller ◽  
R. L. Lawrence ◽  
R. Engel ◽  
G. A. Nielsen

Pulse crop production is expanding in semiarid regions of the Northern Plains, and depends on successful biological N2-fixation. Inoculation failure, resulting in plant N deficiency and economic crop loss, might be alleviated by remedial N fertilizer application. The experiment was conducted using no-till management at two dryland sites in Montana in 1999 and 2000, where field pea and chickpea were grown in cereal stubble. Shoot biomass, shoot biomass N concentration, seed yield and seed N concentration were measured for uninoculated and inoculated controls and compared with remedial fertilizer N applied 0, 4, 6, and 8 wk after seeding. Spectral reflectance was compared for the inoculated and uninoculated controls. For field pea and chickpea, the critical period for fertilizer N application to prevent yield loss occurred within 6 wk of seeding (P ≤ 0.05). Logistic regression models derived from spectral reflectance had overall accuracies of 84 and 60% for detecting uninoculated control treatments in field pea and chickpea, respectively. The field pea model had a high degree of accuracy 6 wk after seeding, indicating it was capable of assisting a decision to apply remedial N fertilizer. Spectral reflectance provided a window of opportunity of 1 wk to apply remedial N fertilizer to attain full yield potential. Key words: Chickpea, field pea, inoculant failure, nitrogen, spectral reflectance


2021 ◽  
Vol 12 ◽  
Author(s):  
Haiqing Gong ◽  
Bilisuma Kabeto Wako ◽  
Yue Xiang ◽  
Xiaoqiang Jiao

Space availability and the maintenance of adequate phosphorus (P) supply in the root zone are essential for achieving high yield and P-use efficiency in maize production by manipulating the root morphology and arbuscular mycorrhizal (AM) fungi colonization. A major trade-off exists between root growth and AM colonization that is influenced by soil P supply intensity and space availability. However, how soil P manipulates the root morphological characteristics and AM colonization to compensate for the limitation of root-growth space induced by high-planting density is not clear. Therefore, pot experiments were conducted to investigate interactions between the root growth and AM fungi by optimizing soil P supply to compensate for limited root growth space induced by high-planting density. Similar shoot biomass and P uptake values were obtained in P200 (200 mg P kg−1 soil) under D = 40 (i.e., diameter of the pot is 40 cm) and P400 under D = 30, and similar values were obtained for root length, tap root length, root angle, lateral root density, and AM colonization. However, the improvement in P supply in the root zone, shoot biomass, and P uptake in P400 under D = 20 were lower than in P200 under D = 30, and there were no significant differences in the root parameters between P200 and P400 under D = 20; similarly, the root growth and AM colonization exhibited similar trends. These results suggest that optimizing P supply in the root zone to regulate the interaction between root morphological traits and AM colonization can compensate for limited root-growth space. Although P supply in the root zone increased after the root-growth space was compressed, it could not meet the P demand of maize; thus, to achieve the most efficient use of P under intensive high-density maize production, it is necessary to optimally coordinate root growth space and P supply in the root zone.


EDIS ◽  
2013 ◽  
Vol 2013 (6) ◽  
Author(s):  
Mongi Zekri ◽  
Tom Obreza

Phosphorus deficiency is not common in Florida citrus groves. If it does occur, it is more difficult to diagnose than nitrogen (N) deficiency or other nutrient element deficiencies. Growth is reduced when P supply is too low. Phosphorus is highly mobile in plants, so when it is deficient, it may move from old leaves to young leaves and other actively growing areas where energy is needed to form seeds and fruit. This 4-page fact sheet was written by Mongi Zekri and Tom Obreza and published by the UF Department of Soil and Water Science, July 2013. http://edis.ifas.ufl.edu/ss581


Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 404 ◽  
Author(s):  
Lianhai Wu ◽  
Martin Blackwell ◽  
Sarah Dunham ◽  
Javier Hernández-Allica ◽  
Steve P. McGrath

The phosphorus (P) supply from soils is crucial to crop production. Given the complexity involved in P-cycling, a model that can simulate the major P-cycling processes and link with other nutrients and environmental factors, e.g., soil temperature and moisture, would be a useful tool. The aim of this study was to describe a process-based P module added to the SPACSYS (Soil Plant and Atmosphere Continuum System) model and to evaluate its predictive capability on the dynamics of P content in crops and the impact of soil P status on crop growth. A P-cycling module was developed and linked to other modules included in the SPACSYS model. We used a winter wheat (Triticum aestivum, cv Xi-19) field experiment at Rothamsted Research in Harpenden to calibrate and validate the model. Model performance statistics show that the model simulated aboveground dry matter, P accumulation and soil moisture dynamics reasonably well. Simulated dynamics of soil nitrate and ammonium were close to the observed data when P fertiliser was applied. However, there are large discrepancies in fields without P fertiliser. This study demonstrated that the SPACSYS model was able to investigate the interactions between carbon, nitrogen, P and water in a single process-based model after the tested P module was implemented.


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