scholarly journals IRRIGATION, WATER RELATIONS, AND CRABAPPLE GROWTH IN ROOT-CONTROL BAGS IN A FIELD NURSERY

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 632e-632
Author(s):  
Roger Kjelgren ◽  
Craig Spihlman

Limited root development of nursery stock in root-control bags facilitates harvest but without irrigation may predispose stock to water stress. The effect of bags and irrigation on growth and water relations of field-grown Malus sieboldii var. zumi were investigated following transplanting as large liners into a silty-clay soil. Predawn leaf water potential (ψ), and midday stomatal conductance (gs) and ψ, were measured periodically through the season. Late-season osmotic potential (ψπ), caliper, leaf area, and root growth were also measured. Non-irrigated treatments exhibited water stress during an extended mid-summer drought, as predawn ψ and particularly gs were less than irrigated treatments, resulting in lower vegetative growth and ψπ. For combined bagged treatments water relations did not differ, but leaf area, root growth, and ψπ, but not caliper, were less than non-bagged trees. Growth measurements and ψπ of non-irrigated bagged trees, however, were consistently lower but nonsignificant than the other treatments. Bag-induced root reduction can limit some top growth even with optimum soil water. Moreover, in terms of potential Type-II errors extrapolated over a conventional production cycle, trees grown in root-control bags in normally non-irrigated soils may be more susceptible to water stress and subjected to further cumulative growth limitation.

1994 ◽  
Vol 12 (2) ◽  
pp. 108-111
Author(s):  
R. Kjelgren ◽  
C. Spihlman ◽  
B.R. Cleveland

Abstract Growth and water relations of irrigated and non-irrigated Malus sieboldii var. zumi produced with and without in-ground fabric containers in a field-nursery setting were investigated. Predawn and midday leaf water potential and midday stomatal conductance were measured periodically through the season, and trunk increment, leaf area, root growth, and osmotic potential were measured in late season. Water potential became more negative and stomatal conductance decreased in non-irrigated treatments during an extended mid-summer drought that resulted in less trunk diameter growth and leaf area. Trees grown in fabric-containers, both irrigated and non-irrigated, exhibited no detectable differences in water relations over the season. These trees did have fewer roots and less leaf area than the trees grown without fabric containers, indicating that in-ground fabric containers can limit growth even when irrigated. Non-irrigated trees in fabric containers were nonetheless affected by water stress as they had the least trunk growth and most negative osmotic potential of all treatments. Careful management practices would suggest increased irrigation frequency during production with in-ground fabric containers to avoid water stress.


1993 ◽  
Vol 23 (9) ◽  
pp. 1766-1774 ◽  
Author(s):  
Stephen G. Pallardy ◽  
Julie L. Rhoads

We conducted comparative studies of putative adaptive morphological attributes in seedlings of two drought tolerant forest tree species: post oak (Quercusstellata Wangenh.) and white oak (Quercusalba L.) and two drought-sensitive species: sugar maple (Acersaccharum Marsh.) and black walnut (Juglansnigra L.). In general, root experiments indicated that seedlings of Quercus species and J. nigra tended to have well-developed taproots and to more rapidly explore deep soil layers than did A. saccharum seedlings. Quercusstellata exhibited a greater capacity than other species for deep root growth. Further, while J. nigra possesses the capacity for vigorous root growth, it also exhibited relatively less root length per unit of leaf area when the soil was moist. When established plants were forced to grow in dry soil, downward root growth was substantially retarded in most species. After several weeks in dry soil, root growth nearly ceased, as seed reserves were depleted and photosynthesis was inhibited by water stress. There was no general redirection of growth to roots when plants were subjected to gradual drying cycles or grown in dry soil. There was no tendency for drought-tolerant species to possess lower rates of cuticular water loss. The species least effective in curtailing water loss after stomatal closure was Q. stellata, the most drought-tolerant species. There were substantial differences among species in leaf abscission responses under drought. Quercus seedlings showed no evidence of water stress induced abscission, even when plants were subjected to severe drought. In contrast, A. saccharum and, particularly, J. nigra seedlings showed substantial leaf abscission under water stress. Production of new leaf area after abscission was observed in non-Quercus species, but was not adequate to compensate for leaf area loss. The results indicated that: (i) very drought-tolerant seedlings of Q. stellata appear to have better relative water supply capacity by roots to leaves than drought-sensitive species in the normal environment presented to newly germinated seedlings; (ii) J. nigra exhibits vigorous root growth after germination that is consistent with its known capacity for stress avoidance, but its allocation of root growth per unit of leaf area is less favorable than the very drought-tolerant Q. stellata; (iii) for this group of species, at least, low cuticular transpiration in water-stressed plants does not appear to be an adaptive trait associated with drought-tolerant species; and (iv) drought-prone sites may present especially detrimental environments for the carbon economy of drought-sensitive species because of the greater probability of recurrent massive leaf abscission.


2021 ◽  
Vol 13 (11) ◽  
pp. 6506
Author(s):  
Roberto Fanigliulo ◽  
Daniele Pochi ◽  
Pieranna Servadio

Conventional seedbed preparation is based on deep ploughing followed by lighter and finer secondary tillage of the superficial layer, normally performed by machines powered by the tractor’s Power Take-Off (PTO), which prepares the seedbed in a single pass. Conservation methods are based on a wide range of interventions, such as minimum or no-tillage, by means of machines with passive action working tools which require two or more passes The aim of this study was to assess both the power-energy requirements of conventional (power harrows and rotary tillers with different working width) and conservation implements (disks harrow and combined cultivator) and the soil tillage quality parameters, with reference to the capability of preparing an optimal seedbed for wheat planting. Field tests were carried out on flat, silty-clay soil, using instrumented tractors. The test results showed significant differences among the operative performances of the two typologies of machines powered by the tractor’s PTO: the fuel consumption, the power and the energy requirements of the rotary tillers are strongly higher than power harrows. However, the results also showed a decrease of these parameters proceeding from conventional to more conservation tillage implements. The better quality of seedbed was provided by the rotary tillers.


Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 128
Author(s):  
Ruihuan She ◽  
Yongxiang Yu ◽  
Chaorong Ge ◽  
Huaiying Yao

Soil salinization typically inhibits the ability of decomposer organisms to utilize soil organic matter, and an increase in soil clay content can mediate the negative effect of salinity on carbon (C) mineralization. However, the interactive effects of soil salt concentrations and properties on C mineralization remain uncertain. In this study, a laboratory experiment was performed to investigate the interactive effects of soil salt content (0.1%, 0.3%, 0.6% and 1.0%) and texture (sandy loam, sandy clay loam and silty clay soil with 6.0%, 23.9% and 40.6% clay content, respectively) on C mineralization and microbial community composition after cotton straw addition. With increasing soil salinity, carbon dioxide (CO2) emissions from the three soils decreased, but the effect of soil salinity on the decomposition of soil organic carbon varied with soil texture. Cumulative CO2 emissions in the coarse-textured (sandy loam and sandy clay loam) soils were more affected by salinity than those in the fine-textured (silty clay) soil. This difference was probably due to the differing responses of labile and resistant organic compounds to salinity across different soil texture. Increased salinity decreased the decomposition of the stable C pool in the coarse-textured soil, by reducing the proportion of fungi to bacteria, whereas it decreased the mineralization of the active C pool in the fine-textured soil through decreasing the Gram-positive bacterial population. Overall, our results suggest that soil texture controlled the negative effect of salinity on C mineralization through regulating the soil microbial community composition.


2021 ◽  
Vol 11 (6) ◽  
pp. 2605
Author(s):  
Giacomo Ferretti ◽  
Giulio Galamini ◽  
Evi Deltedesco ◽  
Markus Gorfer ◽  
Jennifer Fritz ◽  
...  

Using zeolite-rich tuffs for improving soil properties and crop N-use efficiency is becoming popular. However, the mechanistic understanding of their influence on soil N-processes is still poor. This paper aims to shed new light on how natural and NH4+-enriched chabazite zeolites alter short-term N-ammonification and nitrification rates with and without the use of nitrification inhibitor (DMPP). We employed the 15N pool dilution technique to determine short-term gross rates of ammonification and nitrification in a silty-clay soil amended with two typologies of chabazite-rich tuff: (1) at natural state and (2) enriched with NH4+-N from an animal slurry. Archaeal and bacterial amoA, nirS and nosZ genes, N2O-N and CO2-C emissions were also evaluated. The results showed modest short-term effects of chabazite at natural state only on nitrate production rates, which was slightly delayed compared to the unamended soil. On the other hand, the addition of NH4+-enriched chabazite stimulated NH4+-N production, N2O-N emissions, but reduced NO3−-N production and abundance of nirS-nosZ genes. DMPP efficiency in reducing nitrification rates was dependent on N addition but not affected by the two typologies of zeolites tested. The outcomes of this study indicated the good compatibility of both natural and NH4+-enriched chabazite zeolite with DMPP. In particular, the application of NH4+-enriched zeolites with DMPP is recommended to mitigate short-term N losses.


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