首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Following 13‐year treatments of soil pH and nitrogen (N) source in a peach orchard of North Carolina, the concentration of calcium (Ca), magnesium (Mg), N, phosphorus (P), and potassium (K) in leaves, shoots, trunks and roots, as well as soil pH, soil exchangeable Ca, Mg, and K content, were determined. Through liming, higher soil pH treatment enhanced soil Ca and tissue Ca level. Among six N sources examined, the highest values of soil pH and soil Ca, Mg, and K were detected following poultry manure application. Compared to ammonium sulfate [(NH4)2SO4], calcium nitrate [Ca(NO3)2] increased soil pH and soil Ca and K content, but reduced soil Mg. For most of macronutrients examined in peach tissues, the highest levels were found in manure treatment. Mineral N sources containing Ca(NO3)2 resulted in high tissue Ca and low tissue N. In the above‐ground tissues, Mg concentration was relatively low following application of mineral N materials containing Ca, K, or sodium (Na). Acid‐ forming N, especially (NH4)2SO4, reduced tissue Ca and P. The magnitude of impact of liming and N source on macronutrients was tissue‐type dependent, with leaves and other new growth the most sensitive ones while trunks seldom responded to the treatments.  相似文献   

2.
Abstract

The relative effectiveness of Mehlich I (.025N H2SO4 + .05N HCl) and Mehlich III (0.2N CH3COOH + 0.25N NH4NO3 +.015N NH4F + .013N HNO3 + .001M EDTA) extractants as predictors of Mn, Cu and Zn uptake was assessed in a greenhouse experiment with four Delaware soils. The soils were adjusted to eight pH levels by addition of Ca(OH)2 or elemental S, and received comparable amounts of Mn, Cu and Zn as either (1) MnSO4 + CuSO4 + ZnSO4 or (2) Poultry Manure. Mehlich 1 and III extractable Mn and Zn, but not Cu, were well correlated in most instances. Excellent correlations were obtained between Mn uptake and Mehlich I and Mehlich III extractable Mn, for all soils and sources. In general, however, neither Zn nor Cu was found to correlate well with plant uptake. Based on this study, conversion to Mehlich III, as a routine soil test extractant for micronutrients, would not result in a significant improvement over the currently used Mehlich I extractant.  相似文献   

3.
Loading of chemical elements in precipitation at the Solling For the period 1969–1976 (NH4, NO3: 1971–1976) monthly values of concentrations and flows of the ions NH4, H, Na, K, Ca, Mg, Fe, Mn, Al, Cl, NO3, SO4, P and organic bound N in precipitation are passed on. From the correlations between elements the following main ion sources are concluded: sea water (Na, Cl), combustion processes (SO4, NO3, NH4), lime dust after dissolution by H2SO4 and HNO3 (Ca, Mg), soil dust after dissolution by H2SO4 and HNO3 (Al, Fe), leaching from plants (K, NO3, SO4, Mg, Ca), biogenic contaminations (P, organic N, K, NH4, NO3). Seasonal variations in the concentrations are most evident for Na and Cl, less for NH4, SO4 and NO3. During the measuring period the flux of NH4 is significantly increased; for H and SO4, less for NH4, Mg, Ca and Fe, the increasing trend was interrupted in winter 1973/74 (oil crisis). Consequences for sampling are discussed.  相似文献   

4.
This paper describes the effects of elevated CO2 and N fertilization on soils planted with ponderosa pine (Pinus ponderosa) seedlings in short-term greenhouse studies. The high degree of homogeneity in the soils used allowed sensitive evaluation of soil changes in response to treatments. Elevated CO2 had no detectable effect upon soil N availability, but both CO2 and N fertilization caused significant changes in soil available (NH4F/HCl-extractable) P. Some of these changes could be accounted for by plant uptake, some were apparently due to differences in P immobilization (biotic or abiotic). N fertilization caused reductions in exchangeable K, Ca and Mg which could not be accounted for by plant uptake and were probably due to increased leaching. None of the reductions in soil available nutrients observed were of sufficient magnitude to cause nutrient deficiencies over the approximate 1-year duration of these studies.  相似文献   

5.
A greenhouse experiment was conducted to study and quantify the daily uptake rate of nitrate, ammonium, phosphoric acid, potassium, calcium, magnesium, and sulfate (NO3?, NH4+, H2PO4?, K+, Ca2+, Mg2+ and SO42?) and to characterize the uptake daily pattern at different plant ages in a lettuce crop. The uptake rates per gram of plant fresh weight were calculated at 2-hour intervals through sampling the nutrient solution and analyzing it by NO3?/NH4+ conductivity and inductively coupled plasma atomic emission spectrometry (ICP-AES). The uptake rate of nitrogen, phosphorus and potassium (N, P and K) per unit mass of plant decreased with plant age following a reduction in plant relative growth rate. No significant differences were found in the absorption of Ca, Mg and sulfur (S) between the different weeks of growth. The daily absorption patterns showed no preference for the absorption of any of the ions during the daytime. A significant reduction in the absorption peaks of all the ions with increasing plant age was observed.  相似文献   

6.
Abstract

For Southeastern forest soils amounts of P, K, Ca, Mg, and Mn extracted by 0.05 N HCl + 0.025 N H2SO4 (double‐acid) were significantly correlated with amounts extracted by 0.2 N NH4Cl + 0.2 N HOAc + 0.015 N + NH4F + 0.012 N HCl (new‐Mehlich). The new‐Mehlich consistently removed more nutrients than the double acid.

Both P and Mn extracted by the two solutions were significantly correlated with their concentrations in the foliage of loblolly pine (Pinus taeda L.).  相似文献   

7.
Soil was incubated under greenhouse conditions with plant residues having varying phenolic and nitrogen contents. The total plant material added in staggered applications every 4 months was 15 g kg?1 soil and the total incubation period was 12 months.The N-mineralization in these plant residues as influenced by their phenol and N contents was examined. The nitrification of applied (NH4)2SO4 in these amended soils was also investigated under optimum conditions of pH.A high plant-N content resulted in increased N-mineralization of plant residue, but this effect was lowered by the presence of high concentrations of polyphenols in the decomposing residue, most probably due to increased participation of N with polyphenols in the formation of humus fractions.Soils amended with phenol-rich residues did not show any inhibition of nitrification of applied (NH4)2SO4. Possible reasons are discussed. In organic matter decomposition, the quality of the leaf polyphenols appears to determine the degree of inhibition to soil nitrification.  相似文献   

8.
Abstract

Forage intake with potassium/(calcium + magnesium) [K/(Mg + Ca)] values in excess of 2.2 are associated with grass tetany and Mg deficiencies in ruminants. This study was conducted to determine the degree to which forage K and Mg concentrations and K/(Ca + Mg) ratios could be predicted from soil bicarbonate (HCO3) extractable phosphate‐phosphorus (PO4‐P), and saturation extract Ca, Mg, K, sodium (Na), and nitrate‐nitrogen (NO3‐N) concentrations. Crested wheatgrass (Agropyron spp) strains and cultivars representing four ploidy levels were grown in the greenhouse on eight calcareous soils with different saturation extract Ca, Mg, K and K/Mg ratios. The plants were harvested three times. Soil solution K/(Ca + Mg) and K/Mg ratios were the only measured soil parameters that showed a consistent correlation with plant K/(Ca + Mg) ratios. Bicarbonate extractable soil P was positively related to plant P and K uptake in the first harvest, but was not related in the second and third harvests nor was soil P related to plant Ca or Mg content. There was a tendency for the higher ploidy level entries to have higher plant K/(Ca + Mg) ratios. It was concluded that soil K/(Ca + Mg) ratios can be used to predict relative forage K/(Ca + Mg) ratios for grasses grown under similar conditions.  相似文献   

9.
The leaching of Ca, Mg, and K from canopies is a major pathway of these cations into forest soils. Our aim was to quantify rates of canopy leaching and to identify driving factors at the regional scale using annual fluxes of bulk precipitation and throughfall from 37 coniferous and deciduous forests of North and Central Europe. Total deposition of Ca, Mg, K, and H+ was estimated with Na as an index cation. The median canopy leaching increased in the order: Mg (0.11 kmolc ha–1 a–1) < Ca (0.31 kmolc ha–1 a–1) < K (0.39 kmolc ha–1 a–1). Canopy leaching of Ca and K was positively correlated with the calculated total H+ deposition and H+ buffered in the canopy, whereas canopy leaching of Mg was not. With contrasting effects, fluxes of SO4‐S and NH4‐N in throughfall explained to 64 % (P<0.001) of the Ca canopy leaching. Fluxes of NH4‐N and Ca were negatively correlated, suggesting that buffering of H+ by NH3 deposition reduced canopy leaching of Ca. Amount of bulk precipitation and SO4‐S in throughfall were identified as much weaker driving factors for canopy leaching of K (r2=0.28, P<0.01). Our results show that Ca is the dominant cation in buffering the H+ input in the canopy. At the regional and annual scale, canopy leaching of Mg appears to be unaffected by H+ deposition and H+ buffering in the canopy.  相似文献   

10.
Abstract     
In a greenhouse, radish (Raphanus sativus L.), corn (Zea mays L.), soybean (Glycine max Merr), and wheat (Triticum aestivum L.) were grown in soil‐based medium with captan at 60 mg/kg and truban at 30 mg/kg and with different levels of N from (NH4)2SO4 or NaNO3. Growth of radish, soybean, and corn was restricted by NH4‐N compared with NO3‐N. Captan and truban stunted growth of radish and soybean. As NH4‐N or NO3‐N fertilizer increased, the concentration of Ca and Mg in all plants decreased, and the percentage of K in corn, soybean, and wheat increased. Application of captan and truban increased all cation concentrations in corn, wheat, and soybean but decreased Ca concentration in radish. The amount of residual NH4‐N in the medium supplied with (NH4)2SO4 was increased by application of captan or truban. Captan increased the residual NO3‐N in the medium treated with NaNO3. Chemical names used: captan, (N‐(trichloro)methylthio)‐4‐cyclo‐hexene‐l, 2‐dicarboximide); truban, (5‐ethoxy‐3‐trichloromethyl‐l, 2, 4,‐thiadiazole).  相似文献   

11.
Leaf concentrations of nitrogen (N), phosphorus (P), potassium (K), iron (Fe), and manganese (Mn) in ‘Sterling’ muscadine grapes (Vitis rotundifolia Michaux) grown for two years in sand culture were not influenced by different N‐fertilizer sources. Leaf zinc (Zn) and copper (Cu) were higher with ammonium nitrate (NH4NO3)than ammonium sulfate [(NH4)2SO4]. Shoot growth was greatest with NH4NO3. Leaf Ca, Mg, Mn, and Cu content decreased and leaf N increased as N‐fertilizer rates were raised. Plant growth was positively correlated with leaf N, but was negatively correlated with leaf Ca, Mg, Fe, Cu, and Mn content. Percent Mg in the leaves was reduced when N levels, regardless of N source, were raised from the low (1.8 mM) to the middle (5.4 mM) rate. High leaf‐N levels were correlated with lower Ca and Mg in the leaves, indicating a relationship between N fertilization and the late‐season Mg deficiency often observed in muscadine grapes.  相似文献   

12.
With the reduction of sulfur levels in high‐analysis nitrogen (N) and phosphorus (P) fertilizers and in atmospheric deposition, sulfur (S) fertilization may become more important, especially with intensive cropping systems. When high clay content is likely to limit root development into the subsoil, low extractable sulfate‐sulfur (SO4‐S) levels in the topsoil may suggest possible plant response to S fertilization. Even though ammonium sulfate [(NH4)2SO4] is widely used and readily available for plant uptake, field data are limited on the use of (NH4)2SO4 as an S source for soybeans [Glycine max (L.) Merr.]. A study was initiated to determine the effect of S fertilization as (NH4)2SO4 on: (i) the yield, seed weight, grain quality, and leaf and whole‐plant nutrient concentrations of four soybean cultivars grown on soils with high clay content subsoils; and (ii) selected soil chemical characteristics. Sulfur rates were 0, 28, 56, and 84 kg/ha, and soybean cultivars were two Maturity Group IV beans, DeSoto and Douglas, and two Maturity Group V beans, Bay and Essex.

The study was conducted on a Parsons silt loam soil (fine, mixed, thermic, Mollic Albaqualf) in 1986 and 1987, and on a Cherokee silt loam (fine, mixed, thermic, Typic Albaqualf) in 1987. Sulfur application did not significantly affect soybean yield or seed protein or oil concentrations. For whole plants, S concentration increased and N:S ratios decreased with increasing S fertilization. Similar trends were found in soybean leaves. Although N:S ratios of both whole plant and leaf tissue were lowered with S fertilization, the values generally were not below 20:1 which is above cited critical levels. Fertilization with (NH4)2SO4 increased the levels of extractable SO4‐S in the soil, especially in the 15–30 cm depth. The first‐year accumulation of soil SO4‐S with increasing S fertilization appeared to be more at a site that was lower in organic matter.  相似文献   

13.
This research was carried out in order to find out the effect of zinc application on the methods which can be used to determine available iron content of paddy soils. For this purpose, an experiment was carried out in greenhouse conditions by growing maize. The effect of increasing rates of zinc application on biological indexes of maize plants was determined. Eight chemical extraction methods for available iron content of soils were used and these methods are: 0.005 M DTPA+0.01 M CaCl2+0.1 M TEA; 0.005 N HCl+0.025 N H2SO4; 1 N NH4Oac; 0.01 N Na2EDTA+1 N NH4Oac; 2 N MgCl2; 0.01 M Na2EDTA +1 M (NH4)2CO3; 0.01 N Na2EDTA and 0.005 M DTPA+NH4HCO3. The relationships between biological indexes and chemical extraction methods were determined at the end of the experiment. The highest correlation coefficient was determined with the method 0.005 M DTPA+0.01 M CaCl2+0.1 M TEA. The iron content of maize plants decreased with zinc application and dry matter content increased with zinc application.  相似文献   

14.
Summary This study examined the effects of NH inf4 + fertilizers [(NH4)2SO4, (NH4)2HPO4, CO(NH2)2, NH4OH, and NH4NO3] on NH3 loss and the quantity of Ca + Mg, NH inf4 + and NO inf3 sup– in the solution of a calcareous soil (Harkey sicl, Typic Torrifluvent). Various NH4 fertilizers applied at a depth of 5 cm in the soil produced differing NH3 loss characteristics. Applying (NH4)2SO4 (AS) resulted in high volatile NH3 losses as compared with NH4OH (AH) and (NH4)2CO3 (AC). The AS treatment formed an equal molar amount of CaSO4, which increased the mobility of ammonium, while AH and AC treatments caused Ca precipitation and decreased ammonium mobility. Leaching the AS system before NH3 loss could occur resulted in the most rapid nitrification rate. Lower nitrification rates were found with AH and AC than AS under the same conditions. Surface placement of NH4 fertilizers resulted in variable leachate contents of Ca + Mg. Ammonium sulfate reacted with CaCO3 either to solubilize some Ca + Mg or simply to replace exchangeable Ca + Mg with NH4, while AH, AC, and (NH4)2HPO4 (DAP) precipitated essentially an equivalent molar amount of soluble and adsorbed Ca + Mg. Use of NH4NO3, which does not form an insoluble calcium precipitate, resulted in the leaching of an equivalent molar amount of exchangeable Ca + Mg from the Harkey soil.The authors are Professor and former laboratory technician, respectively, at Texas A&M Research Center at El Paso, 1380 A&M Circle, El Paso, TX 79927, USA  相似文献   

15.
Abstract

The effect of soil pH on the exchangeability and solubility of soil cations (Ca, Mg, Na, K, and NH4‐N) and anions (NO3‐N, Cl, and P) was investigated for 80 soils, spanning a wide range in physical and chemical properties and taxonomic groups. This information is needed from environmental and agronomic standpoints to estimate the effect of changes in soil pH on leachability and plant availability of soil nutrients. Soils were incubated with varying amounts of acid (H2SO4) and base (CaCO3) for up to 30 days. Although acid and base amendments had no consistent effect on cation exchangeability (as determined by neutral NH4OAc), amounts of water‐soluble Ca, Mg, Na, K, NH4‐N, and P decreased, while NO3‐N and Cl increased with an increase in soil pH. The increase in cation solubility was attributed to an increase in the negative charge of the soil surface associated with the base addition. The change in surface electrostatic potential had the opposite effect on amounts of NO3‐N and Cl in solution, with increases in N mineralization with increasing soil pH also contributing to the greater amount of NO3‐N in solution. The decrease in P solubility was attributed to changes in the solubility of Fe‐, A1‐, and Ca‐P complexes. The logarithm of the amount of water‐soluble cation or anion was a linear function of soil pH. The slope of this relationship was closely related (R2 = = 0.90 ‐ 0.96) to clay content, initial soil pH, and size of the cation or anion pool maintaining solution concentration. Although the degree in soil pH buffering increased with length of incubation, no effect of time on the relationship between cation or anion solubility and pH was observed except for NO3‐N, due to N mineralization. A change in soil pH brought about by acid rain, fertilizer, and lime inputs, thus, affects cation and anion solubility. The impact of these changes on cation and anion leachability and plant availability may be assessed using the regression equations developed.  相似文献   

16.
Rabbiteye blueberries grown in sand culture were subjected to varying levels of N fertilization (0 ‐ 81 mg N/liter) applied in aqueous solution at the rate of 250 ml/plant daily. Essential elements other than N were kept constant. Shoot growth and leaf concentration of N, P, K, Mg, Ca, Mn, Fe, Cu, B, Zn, Co, and Al were determined. Shoot growth and percent leaf N increased with increased N levels. Shoot growth increased little at N fertilization levels of 0 ‐ 9 mg/ liter but increased rapidly at higher rates. N content in leaves followed a quadratic curve, with % N in leaves increasing more rapidly from 0 to 27 mg N/liter than from 27 to 81 mg N/liter fertilization levels. Leaf concentration of K, Ca, Mg, Mn, B, and Ca decreased linearly as N levels increased. Total content of all elements increased as N fertilization increased. Visual N deficiency became increasingly evident as % N content decreased below 1.4% N.

Nitrogen, the most utilized element in plants, is usually the first to become deficient in sandy soils low in nutrient content (1). Rabbiteye blueberries (Vaccinium ashei Reade) are often grown on acidic, sandy, upland coastal plains soils that are low in cation exchange capacity, organic matter content, and available nutrients. In these acidic soils, NH4N is more available than in neutral soils (2). The NH4N source appears to be more suitable for blueberry growth, resulting in greater nutrient uptake, plant growth, and % N of leaf tissue than did the NO3N sources (5,6).

Nitrogen deficiency symptoms in rabbiteye blueberries are characterized by small, yellow and/or red leaves and stunted plants (3). Since young rabbiteye plants are very sensitive to fertilizer, similar chlorosis symptoms (yellowing or reddening of leaves) can be associated with over‐fertilization, possibly due to root damage (7). Cain (2) found that leaves from healthy container‐grown highbush (V. corymbosum L.) blueberry plants contained about 2% N and higher levels of K and Ca than field‐grown plants. Greenhouse and Field studies indicate that leaf N content in rabbiteye blueberries is usually lower, ranging from about 1.5 to 1.8 (3,7,8). Increased N fertilization decreased the nutrient uptake of other essential elements (Ca and Mg) in rabbiteye blueberries (6). In highbush, Popenoe (4) indicated that a depression of P and K might occur under conditions of high N levels.

This study was initiated to ascertain the effect of NH4N fertilization levels on uptake patterns of essential elements and to determine the relationships of N fertilization, leaf N content, plant growth, and visible deficiency symptoms.  相似文献   


17.
Growth chamber experiments of canola (Brassica napus L.) and spring wheat (Triticum aestivum L.) were conducted using three soils testing low in extractable sulfate (9–12 mg/kg). Experiments were designed to determine how the three soils compared in plant available sulfur (S) and to test the effects of various rates of potassium sulfate (K2SO4) and gypsum on the elemental composition and dry matter yield of the two crops. Based upon plant response, the Queens sandy loam soil appeared to have the least amount of plant available S of the three soils. There was no yield increase associated with S applied to either crop. Canola plants in each soil responded to increased applications of S with greater S uptake and considerably lower nitrogen:sulfur (N:S) ratios. Of the three soils used, only the wheat plants grown in the Queens soil responded to S applications through increased S uptake and a lower N:S ratio. Both sources of S were equally effective in providing available S to the plants.  相似文献   

18.
Due to the high levels of crude protein in the achene, sunflower (Helianthus annuus L.) is one of the main oilseeds grown worldwide, particularly for the oil and meal production for animal feed. Despite these advantages, there are few studies on nutrient use efficiency under tropical conditions, especially nitrogen (N). The experiment was conducted in greenhouse conditions to evaluate the effects of N sources and rates on sunflower achene yield (AY), yield and physiological components, and nutritional status of sunflower. The five N sources (calcium nitrate (Ca(NO3)2), potassium nitrate (KNO3), ammonium nitrate (NO3NH4), ammonium sulfate ((NH4)2SO4), and urea (CO(NH2)2)), and four N rates (0, 50, 100, and 200 mg kg?1) were studied. AY was reduced with the ammonia sources application from the 100 mg N kg?1. Plant height and capitulum dry weight (CDW), capitulum diameter, shoot dry weight (SDW), and chlorophyll content were significantly related with N sources and rates. Except for potassium (K), the N rates changed the N, P, Ca, Mg, and S concentration in the leaves and N concentration in achene. In the comparison of sources, on the average of N rates, urea application was more effective than the other N fertilizers in the AY.  相似文献   

19.
Rainwater samples (N = 51) were collected at Rampur, an areafree from anthropogenic activity during the monsoon of 1997 and1998. The concentration of ions follows a general pattern as Ca> NH4 > Mg > SO4 > Cl > F >Na > NO3 > K > HCOO >CH3 COO. The pH of precipitation ranges between 5.9 and 7.4. The levels of Ca and Mg at this site are higher than otherremote sites, probably dominated by particles of soil origin.Good correlation between Ca, NO3, SO4, HCOO and CH3COO indicate that a fraction of NO3, SO4, HCOOand CH3COO may be derived from soil or associated with Ca and Mg after neutralization. The order of neutralization factorCa (2.19) > NH4 (1.26) = Mg (1.26) indicates that majorneutralization occurred by Ca. Factor analysis suggested thatCa, Mg, Na, K, NO3, SO4, HCOO and CH3COO arecontributed by soil. NH3 is known to exist as(NH4)2SO4, NH4NO3 and NH4Cl. Theymay be formed in the atmospheric water droplets by scavenging ofaerosols and reaction of gaseous species.  相似文献   

20.
《Journal of plant nutrition》2013,36(12):2603-2612
ABSTRACT

The influence of nitrogen (N) sources on biomass yield and nutrient uptake of wheat (Triticum aestivum L.) under saline conditions was studied in a greenhouse experiment. Six different forms of N {nitrate-N as Ca(NO3)2, urea-N [CO(NH2)2], ammonium-N as (NH4)2SO4, nitrate-N+urea-N, nitrate-N+ammonium-N and a control (no N fertilizer)} were factorially combined with three levels of salinity to give a total of 18 treatments that were replicated three times. Each of the five levels of applied N was at the rate of 100?kg?ha?1. The salinity levels (ECe) were 6.2 and 12.1?dSm?1, denoted as S 1 and S 2 and untreated soil (S 0), respectively. A basal dose of phosphorus (P) and potassium (K) was also applied. Five wheat plants were grown in each pot for six weeks. Data were collected for shoot and root biomass and shoot samples were analyzed for N, P, K, calcium (Ca), magnesium (Mg), sodium (Na), chloride (Cl), and micronutrients contents. Plant growth and nutrient uptake were influenced by both salinity and source of N. As expected, increasing salinity decreased dry matter production of shoot and root, whereas N application increased plant growth across all levels of salinity. The total dry biomass (shoot and root) of wheat was significantly higher in combined N treatments than in single sources. Irrespective of N forms most of the nutrient concentrations in the shoot was increased with increasing level of salinity. Among the fertilizers the concentration of cation was higher in nitrate-treated plants than in other forms of N. Ammonium-N and urea-N tended to inhibit the uptake of cations compared to nitrate-N under saline conditions. The trend for P and Cl concentration was almost opposite to that of cations concentration in the shoot. The uptake of nutrients seemed to be influenced by cation–anion balance in soil-plant system. Nitrogen concentration of shoot was greatly enhanced by all forms of N in the following order: Ni>NiAm>Am>NiUr>Ur>control. The interactive effect of salinity and fertilizer on iron (Fe), manganese (Mn), and zinc (Zn) contents was not consistent. Among the fertilizers the concentration of trace elements in the shoot was also not significantly different. It was concluded that the plant growth and nutrient concentration of shoot could depend upon N source and level of salinity. The mixed application of both ammoniacal and nitrate forms of N could possibly be conducive to plant growth in salt affected soils.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号