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Genetic Variability in Tetany Potential of Orchradgrass as Influenced by Application of Dairy Manure and Chemical Fertilizer



M. Hasinur Rahman and S. Saiga
 
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ABSTRACT

The objectives of this study were to compare K, Ca and Mg utilization and grass tetany potential among the high and low magnesium containing strains and commercial cultivars of orchardgrass in response to application of dairy manure and chemical fertilizer. The study was conducted from 2002 through 2003 in northern Honshu Island, Japan on sandy loam Andisol. Highest plant dry matter production was recorded with the application of chemical fertilizer. Soil properties varied with application of manure. Potassium concentration in shoot tissue increased from 2002 to 2003 in all the treatments irrespective of strains and cultivars. However, calcium concentration in shoot tissue decreased from 2002 to 2003 in all the treatments irrespective of strains and cultivars. High magnesium containing strains almost showed low potassium and high magnesium and calcium concentrations in all the treatments. Concentrations of K, Ca and Mg in shoot tissue were highest as a result of dairy manure application and lowest by chemical fertilizer application. The grass tetany potentials were higher in 2003 than 2002. The grass tetany potential was lowest in all the cultivars and strains during fertilization with chemical fertilizer. High magnesium containing strains were less grass tetany prone than the others irrespective of treatments. The correlations between equivalent ratio and K were significantly positive; the correlations involving equivalent ratio, Ca and Mg were negative, however, regardless of treatments and years.

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M. Hasinur Rahman and S. Saiga, 2007. Genetic Variability in Tetany Potential of Orchradgrass as Influenced by Application of Dairy Manure and Chemical Fertilizer. International Journal of Soil Science, 2: 29-39.

DOI: 10.3923/ijss.2007.29.39

URL: https://scialert.net/abstract/?doi=ijss.2007.29.39

INTRODUCTION

Incidence of grass tetany, a metabolic disorder of ruminants has been increased in all over the world. The reason for the greater incidence of grass tetany is the increased use of N and K fertilizers or dairy manure on forage production. Increased levels of K and N depress Mg uptake by forage that affects the availability of Mg to ruminants. Tetany occurred more frequently when the temperature is low but the meteorological conditions are favorable for good plant growth (‘t Hart, 1960). Grass tetany prevention and treatment is based on the use of Mg supplements. However, Mg supplementation is often not commenced until symptoms are severe and it may be too late to prevent mortality (Harris et al., 1983). There is increasing evidence that ion uptake by plants is under genetic control (Clark, 1983; Saric, 1983). Genetic variability for K, Mg, Ca or K/(Ca+Mg) has been reported in several temperate grass species including perennial ryegrass (Cooper, 1973; Crush, 1983; Easton et al., 1997), tall fescue (Nguyen and Sleper, 1981), prairie grass (Rumball et al., 1972), orchardgrass (Stratton and Sleper, 1979) reed canarygrass (Hovin et al., 1978), Italian ryegrass (Hides and Thomas, 1981), crested wheatgrass (Mayland and Asay, 1989; Vogel et al., 1989; Asay et al., 1996), Russian wild ryegrass (Asay and Mayland, 1990) and festulium (Buckner et al., 1981). In this context, plant-breeding programs have been started to increase available Mg on Italian ryegrass (Moseley and Griffiths, 1984; Moseley and Baker, 1991), tall fescue (Sleper et al., 1989; Mayland and Sleper, 1993), perennial ryegrass (Binnie et al., 1996) and orchardgrass (Saiga et al., 2002).

Orchardgrass (Dactylis glomerata L.) is the major perennial grass species sown in temperate region of Japan caused grass tetany in cattle with high mortality rate. The K/(Ca+Mg) ratio on the mole equivalent basis has been used to ascertain the possibility of grass tetany (hypomagnesaemia) in high producing dairy cattle and in the diets, values>2.2 is appear to be critical for the onset of grass tetany (Kemp and t’Hart, 1957; Butler, 1963; Grunes et al., 1970; Ritter et al., 1984). Management practices and climatic conditions may affect on grass tetany potential (K/(Ca+Mg)) as large environmental effects on herbage mineral concentration were detected (Rabinson et al., 1989; Smith et al., 1999) and nutrient uptake is governed by the interplay of the nutrient supplying power of a soil with the nutrient demand exerted by the plant root (Barber, 1984). Application of fresh farmyard manure to maize (Zea mays L) and Italian ryegrass (Lolium multiflorum Lam.) grown in Andisols resulted in equivalent ratios above 2.2 (Ito and Miyazawa, 1984). Long-term application of fertilizer and fertilizer/barnyard manure to forage maize grown in sandy loam soil resulted in K/(Ca+Mg) ratio as high as 4.0 (Kagata et al., 1999). However, the effects of dairy manure applications to orchardgrass cultivars grown in Andisols in terms of grass tetany potential are not elucidated. So, the main objectives of this study were to compare K, Ca and Mg utilization and grass tetany potential of orchardgrass strains and cultivars fertilized with dairy manure and chemical fertilizer in Andisol of northeast Honshu Island of Japan.

MATERIALS AND METHODS

Experimental Field and Climatic Conditions
The field was established in 1999 in sandy loam Andisol with pH 6.03, exchangeable K2O, CaO and MgO were 48, 443 and 53 mg 100 g-1 soil, respectively and a soil organic matter content of 183.97 g kg-1 in the top 15 cm. The experiment was started in March and continued until October for 2002 and 2003 at the Uwadai field of Iwate University, Japan. The climatic conditions during the experiment were shown in Table 1.

Plant Materials
Orchardgrass (Dactylis glomerata L.) was used in this experiment, because it is the most productive forage and widely cultivated in northeast Japan. Orchardgrass including two commercial cultivars viz.


Table 1: Meteorological data of the field area during the experiments
Image for - Genetic Variability in Tetany Potential of Orchradgrass as Influenced by Application of Dairy Manure and Chemical Fertilizer

Okamidori and Akimidori and four experimental strains viz. HighMgE, HighMgM, LowEq and LowMg which differed in morphological and chemical features as well as in genetic variability (Saiga et al., 2002) were used in this experiment. Okamidori, HighMgE, HighMgM and LowEq were bred for high Mg containing plants.

Treatments
Dairy manure (DM), chemical fertilizer (CF) and dairy manure and chemical fertilizer (DMCF) were broadcasted in each year on 26 March at the rate of 1 t/0.1 ha, 10 kg/0.1 ha and 1/2 t+5 kg/0.1 ha, respectively. The N, P, K composition of dairy manure was 1, 2and 1.4%, respectively. The experimental site had no previous history of dairy manure application and we conducted experiment during 2002 and 2003. At neither plot were weeds a significant problem during the experiment. Hand weeding was used, if and where necessary to control spot outbreaks.

Plant Harvest and Soil Analysis
Forage was harvested (6 cm cutting height) four times at 27th April, 26th June, 25th August and 26th October maintaining 60 days growing period during 2002 and 2003. Soil samples (0-15 cm) were collected at the day of last harvest in each year using core sampler and analyzed for soil bulk density (Blake and Hartge, 1986), hardness, porosity (Danielson and Sutherland, 1986), moisture content (Gardner, 1986) at field condition. The pH of soils was determined in a 1:2.5 soil to water suspension (Jackson, 1973) by a digital pH meter. Soil organic matter estimated according to Ball (1965).

Mineral Analysis
After harvesting, the sample was dried at 80°C for 24 h in a forced-air oven. After drying, the samples were ground to pass a 0.5 mm screen with a cyclone mill and 0.5 to 1.0 g sample was pressed (with a coherent disc of 2.5 cm) by applying 15.0 tons pressure to make a pellet with a uniform surface. After that the concentrations of magnesium (Mg), potassium (K) and calcium (Ca) of the both sites of the pellet were measured with a live time of 100s by energy reflectance x-ray fluorescence analyzer (ERF; JEOL Co., JSX-3220, Element Analyzer) as described by Hutton and Norrish (1977) and Norrish and Hutton (1977). Each plant sample was replicated three times. The K/(Ca+Mg) was computed on a mole equivalent basis. In this study the average values for four harvests in dry matter production and nutrients content were evaluated and the values for changes in soil properties were evaluated over two years.

Experimental Design
The experiment was set up as a split plot design with two dairy manure rates and one fertilizer treatment (main plots) and grass genotypes (subplots) as random effects replicated three times with an individual plot area of 8.6 m2.

Statistics
Analysis of variance was used to detect significant differences between the main experimental factors, namely (1) effect of treatment and (2) effect growing season. The relative proportions of sum of square (%SS) due to treatments, growing seasons and their interactions to the total SS were calculated to clarify the effects of treatments, growing seasons and interactions of these variables, respectively. Duncan’s Multiple Range Test (Duncan, 1955) was conducted to compare results with the variables at a 5% level of significance. The Least Significant Differences (LSD) test was also used to determine whether differences between growing seasons were statistically significant (p<0.05). Pearson correlation coefficients among nutrients were performed. All statistical analyses were conducted using lease square ANOVA procedure of SAS at the Computer Center of Iwate University, Japan.

RESULTS AND DISCUSSION

Selected Soil Properties and Dry Matter Yield
Table 2 showed that soil properties and dry matter yield was affected by treatment, growing season and interaction of those variables. Treatment had a predominant effect on soil bulk density, hardness and porosity explained 57.9, 81.2 and 64.0%, of the total variations, respectively, as compared with growing season and treatment x growing season. Soil pH was affected by treatment, growing season and treatment x growing season accounting for 16.2, 58.0 and 25.8% of the total variance in the data, respectively. Growing season had a predominant effect on soil organic matter explained 79.7% of the total variations, as compared with treatment and treatment x growing season. Soil bulk density decreased and as a consequence porosity increased with the application of manure although differences in porosity were not statistically significant (Table 3) among the treatments. In our experiment soil bulk density significantly decreased with application of dairy manure but Eghball (2002) reported that soil bulk density was found unaffected by application of manure or compost. Significantly higher soil hardness was found in CF treatment than the other treatments. Highest soil pH and organic matter was recorded in DM treatment. It is resulted that the organic matter content of composted municipal solid waste exceeds 25% and its addition to most soils increases the organic matter content (Schrader, 1967), total pore space (Pagliai, 1981) and pH of acid soils (Sanderson, 1980; Scanlon et al., 1973) and decreases soil bulk density (Mays and Giordano, 1989; Guidi and Petruzzelli, 1989). Magdoff and Amadon (1980) stated that the effect of inorganic-N fertilizer on lowering soil pH could be counteracting by application of manure. They observed that application of manure increased organic matter as well. In our experiment soil pH decreased causes by application of chemical fertilizer. Dairy manure raised the soil pH when no chemical fertilizer was added to soil. A large amount of bases related to N was probably responsible for the influence of dairy manure on soil pH. Eghball (2002) observed that soil surface pH significantly increased with N-based manure or compost application but decreased with NH4-N fertilizer application as compared with check.

Dry matter yield was significantly affected by treatment and growing season, accounting for 47.6 and 38.6% of the total variance in the data, respectively (Table 2). Dry matter yield was also significantly affected by treatmentxgrowing season interaction indicated that there were treatment-specific differences in dry matter yield to growing season.


Table 2: Overall effects of treatment and growing season on different variables using ANOVA
Image for - Genetic Variability in Tetany Potential of Orchradgrass as Influenced by Application of Dairy Manure and Chemical Fertilizer

Table 3: Dry matter yield and some selected soil properties as a function of dairy manure and chemical fertilization application over two years
Image for - Genetic Variability in Tetany Potential of Orchradgrass as Influenced by Application of Dairy Manure and Chemical Fertilizer
1Means in within treatments followed by same letter(s) are not statistically different (p<0.05)

Dry matter yield increased with growing season for DM treatments and decreased for other treatments (Table 3). Present results were in good agreement with those of Kagata et al. (1999).

Potassium, Calcium and Magnesium Concentration
The analysis of variance for K, Ca and Mg of this study is listed in Table 4 through 6. The fit of the model (R2) was very good for all the variables (K>Ca>Mg). The effects of treatment, strain/cultivar and interaction of these variables were statistically significant with the exception of treatment effect on Mg in 2002 growing season. The coefficients of variation (CV) over two growing season were 3.43, 4.01 and 7.24% for K, Ca and Mg, respectively. Herbage K concentration increased after first season in all the treatments (Table 4). Low Mg containing plants showed greatly higher K than high Mg containing plants. Application of compost showed highest concentration of K in all the plants than the other treatments. Calcium concentration of plants decreased with season progressed in all the strains and commercial cultivars (Table 5). Low Mg containing plants showed greatly lower Ca than high Mg containing plants. Application of dairy manure showed highest concentration of Ca in all the plants than the other treatments. Calcium content in forage may increase by applying nitrogenous fertilizer. Slowing of pasture growth by any means or seasonal decline soil temperature increased forage Ca level (Underwood and Suttle, 1999). Magnesium concentration of plants decreased with advancement of growing season in all the strains and commercial cultivars for CF and DMCF treatments and increased for DM treatment (Table 6).


Table 4: Effect of dairy manure and chemical fertilizer on K concentration of orchardgrass
Image for - Genetic Variability in Tetany Potential of Orchradgrass as Influenced by Application of Dairy Manure and Chemical Fertilizer
1Means in a column within a treatment and year followed by same letter (s) are not statistically different.2Least significant different (LSD) at p<0.05 between growing seasons (columns). 3*, **, *** represent statistical significant at 0.01, 0.001 and 0.0001 probability levels, respectively

Table 5: Effect of dairy manure and chemical fertilizer on Ca concentration of orchardgrass
Image for - Genetic Variability in Tetany Potential of Orchradgrass as Influenced by Application of Dairy Manure and Chemical Fertilizer
1Means in a column within a treatment and year followed by same letter(s) are not statistically different.2Least significant different (LSD) at p<0.05 between growing seasons (columns).3*, **, *** represent statistical significant at 0.01, 0.001 and 0.0001 probability levels, respectively

Significant increases were observed by Saiga et al. (1997) as the season progresses for Mg concentration in orchardgrass grown in Andisol. Magnesium concentration was also found higher in all the high Mg containing plants. Application of dairy manure showed highest concentration of Mg in all the plants. On the other hand, application of chemical fertilizer showed lowest concentration of Mg in all the plants. Nitrogen fertilization increased the concentration of higher fatty acids in plants and this may depress the availability of Mg (Grunes, 1973).

The Equivalent Ratio
The tetany potential increased from season 2002 to 2003 and it was below the critical level for all the treatments irrespective of strains and commercial cultivars (Table 7). The lowest values were recorded in case of chemical fertilizer application. Animal consuming low Mg containing orchardgrass would be more tetany prone than those of high Mg containing orchardgrass as a result of dairy manure application.

Relationship Among the Nutrients
Correlation coefficients were calculated for each year for individual treatment as well as for years combined (Table 8). Potassium was significantly and positively correlated with K/(Ca+Mg) irrespective of year and treatment. On the other hand, Ca and Mg was significantly and negatively correlated with K/(Ca+Mg) irrespective of year and treatment. In years combined Ca was more closely correlated with K/(Ca+Mg) for DM treatment and Mg was closely correlated with K/(Ca+Mg) for CF and DMCF treatments.


Table 6: Effect of dairy manure and chemical fertilizer on Mg concentration of orchardgrass
Image for - Genetic Variability in Tetany Potential of Orchradgrass as Influenced by Application of Dairy Manure and Chemical Fertilizer
1Means in a column within a treatment and year followed by same letter(s) are not statistically different.2Least significant different (LSD) at p<0.05 between growing seasons (columns).3*, **, *** represent statistical significant at 0.01, 0.001 and 0.0001 probability levels, respectively

Table 7: Grass tetany potential in orchardgrass as a result of dairy manure and chemial fertilizer applications
Image for - Genetic Variability in Tetany Potential of Orchradgrass as Influenced by Application of Dairy Manure and Chemical Fertilizer
1Means in a column within a treatment and year followed by same letter(s) are not statistically different.2Least significant different (LSD) at p<0.05 between growing seasons (columns).3*, **, *** represent statistical significant at 0.01, 0.001 and 0.0001 probability levels, respectively

Table 8: Linear correlation coefficients of K, Ca, Mg and K/(Ca+Mg) for orchardgrass
Image for - Genetic Variability in Tetany Potential of Orchradgrass as Influenced by Application of Dairy Manure and Chemical Fertilizer
1*Significant at the 0.05 level; **Significant at the 0.01 level; NSNot significant

In years combined K was negatively correlated with Ca and Ca was positively correlated with Mg. Mayland and Asay (1989) worked with the genetic variability of K, Ca and Mg in crested wheatgrass and found that Ca significantly and positively correlated with Mg and K and negatively with K/(Ca+Mg). They observed that Mg was significantly and positively correlated with Ca and K and negatively with K/(Ca+Mg). In that study it was also noted that K/(Ca+Mg) was significantly and negatively correlared with Ca and Mg and positively with K.

CONCLUSIONS

Genetic variability in tetany potential was evaluated for orchardgrass when grown in Andisol fertilized with dairy manure and chemical fertilizer. During the two growing seasons no symptom was observed in equivalent ratios of above 2.2. The high Mg containing cultivars showed low equivalent ratio in all the treatments. Although no negative effects were observed in relation to tetany potential due to application of dairy manure but from the view point of soil oxygenation, it should be emphasized that large additions material such as slurry, sewage and/or dairy manure must be applied with care, because while they increase oxygen demand they may simultaneously impede gas exchange by clogging the soil pore. In the above mentioned case, when the soil oxygenation is insufficient other gases such as CH4, H2S, N2O, C2H2 and H2 may occur in the soil air. The presence of any of these gases, despite low concentrations, is an important indicator of the status of the soil quality.

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