Study on the effect of chemical fertilizer and manure on the chemical properties of orange leaf (Thompson Novel)

Chemical fertilizers have important role in increasing crop production in unit square meter, but studies showed that using these fertilizers for long period with strong salts in them cause damage to soil physical and chemical properties like soil infiltration, bulk density and decrease in plant root penetration that ultimately decrease crop production. The aim of this research was to estimate desirable proportions of chemical fertilizers and organic manure with the aim of reduction in consumption of chemical fertilizers
Methods and materials. For the study of the combined effect of different chemical fertilizers and manure (sheep) to reach suitable fertilizers combination (Thompson novel orange) an experiment was conducted at 2013 in one of the orchard at Sari district with low organic C. This research carried out on five years old citrus threes. This experiment carried out as factorial experiment on the base of complete randomized block design with 9 treatments and three replications. Treatments included three manure levels (0, 6 and 12 kg per) and three levels of macro fertilizer including potassium sulphate, ammonium sulphate and super phosphate triple (0, 30 and 60 percent on the bases of soil test).
Result and discussion. The results of analysis of variance on orange leaf nitrogen showed that simple effect of chemical fertilizers and organic manure and their interactions were significant at 5% level. The interaction between factors under studies for this trait showed that chemical fertilizers are under influence of organic manure. The results of analysis of variance showed that simple effect of chemical fertilizers and interaction effects of chemical fertilizers and organic manure on orange leaf phosphorus were significant at 1% level. Mean comparisions showed that highest phosphorus absorption were related to 60% chemical fertilizers use and 6 and 12 kg manure which were statically in same group. The results of analysis of variance showed that the simple effect of different levels of chemical fertilizers and its interactions with manure on orange leaf potassium absorption were significant at 1% level. Mean comparison of interactions showed that the highest potassium absorption were with T8 treatment. The analysis of variance for sulphur absorption showed that simple effect of chemical fertilizer and manure were significant at 1% level and their interactions were significant at 5% level. The results from analysis of variance showed that simple effect of chemical fertilizer and its interaction with manure on orange leaf calcium absorption were significant at 5% level and simple effect of manure on orange leaf absorption were significant at 1% level.
The highest nitrogen, phosphorus and potassium of Thompson leaf were obtained with application of 60% chemical fertilizer and 6 kg manure. The highest absorption of calcium, magnesium, Iron, manganese and zinc in Thompson orange leaf were obtained with 30% chemical fertilizer application and 12 kg manure.