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Abstract SUMMARY Field experiments were carried out at the Research and Experiment Station , Faculty of Agriculture at Moshtohor , Zagazig University in the two successive seasons ( 1981/1982 and 1982/1983) to investigate the effect of soil application of various nitrogen levels, and various concentrations of di~ferent foliar micronutrients on the quantitative and qualitative characters of Egyptian clover and ryegrass mixture • Soil analysis of the experimental plots indicated a clay soil texture with pH value of 7.5 Each experiment included fourty-eight treatments which were the combination of four soil nitrogen levels, ( i.e. 0.0 , 30 , 60 and 90 kg N/fad) ; four micronutrients ( Zn , Fe , Mn and Cu ) and three concentrations each of thesemicronutrients ( 0 ,0.1 ,0.2 ; 0 ,0.2 ,0.4 ; o ; 0.2 , 0.4 and 0, 0.1 , 0.2 % ) respectively. The design of the experiment was split-split plot , with five replications • The four nitrogen levels were randomly arranged in the main plots , the four micronutrients were assigned randomly in the sub-plots t and their concentrations were devoted to the sub-sub plots. The area of the experimental unit was 10.5 sq.m. _ 139- Egyptian clover and Italian ryegrass were sown as a mixture using seed rate of 15 kg and 2.5 kg, respectively for obtaining a mixture forage stand of 75 % Egyptian clover and 25 % Italian ryegrass • The main results could be summarized as follows :- A - Forage yield (1) In general , applying either 30 or 60 kg N/fad could be enough to produce high forage yield over the majority of the individual cuts in the two growing seaSons • (2) The increase in the total forage yield of the mixture was greater by applying the first N level ( 30 kg N/fad) compared to the control • This increase in forage yield started to be slightly lower at the subsequent higher levels of N application .Applying 60 kg N/fad is the recommended rate for obtaining highly reasonable forage yield under the circumstances of these experiments • (3) Foliar application of Mn , Zn , or Cu ; each had a pronounced effect in increasing the forage yield of the mixture. However, Mn ranked the first, followed by Zn then Cu for producing the highest forage yield of the majority of the individual cuts in the two growing seasons • Meanwhile Fe was the last in this rank. Either Zn or Cu at 0.1% concentration, and either Hn or Fe at 0.2% concentration produced the highest forage yield of most of the individual cuts and the total yield • (4) No interaction effect of N levels and micronutrient treatments was found on the forage yield of the individual cuts or~the total yield • Combined analysis for the forage yield revealed that : (5) Applying 60 kg N/fad could be the recommended rate for nitrogen application as far as the cuts and the total forage yield were concerned • (6) Manganese produced the highest total forage yield, followed by Zn , then Cu followed by Fe with a significant difference between each of the previously mentioned micronutrients • (7) Applying 0.2% Mn, 0.1% Zn , 0.1% Cu, and 0.2 %” Fe produced the highest forage yield of each of the four cuts and the total yield as well, where the interaction between the applied micronutrients and their concentrations effects was significant in all cuts except for the second one • B - Dry yield: (8) Applying 60 kg N/fad could be the recommended N level for producing the highest dry yield of the different cuts and the total yield. (9) Manganese had the highest effect in producing the top total yield, then Zn followed by Cu , then Fe , Without significant differences between the first three micronutrients • Whereas, the difference in the effect between the first and last one was significant. (10) Manganese at 0.4% significantly produced the highest dry yield of all cuts of the two seasons compared with the control • That concentration produced the highest total dry yield • However , the other micronutrlents , Zn , Cu and Fe at the first concentration level 0.1 , 0.1 and 0.2 % , respectively produ~ed the highest yield of the cuts and the total yield as well where Zn followed Mn , then Cu followed by Fe in their effects • Combined analysis for the dry yield revealed that (11) Applying 60 kg N/fad is recommended N level for producing the highest dry yield of the cuts and the total yield of the mixed stand as well • (12) Manganese application at 60 kg N/fad could be suggested for practical and better production , where the interaction effect was significant • It is also Observed that ”either Cu or Fe produced the lowest dry yield of most cuts at almost all nitrogen application levels • (13) Highest dry yield.was produced by applying Mn , then Zn,followed by Cu , then Fe. (14) Applying 0.4% Mn produced the highest dry yield in all cuts , and the total dry yield as well. However, 0.1% Zn , 0.2% Fe , and 0.1% eu significantly produced the highest dry yield of the cuts and the total yield c - Plant height (15) Increasing nitrogen application levels caused a continuous significant increase in the plant height of the two components of the mixed stand. However, Egyptian clover plants responded to nitrogen application levels up to 60 kg N/fad, and ryegrass plants up to . 90 kg N/fad. (16) Manganese was the most important micronutrient in producing the tallest ryegrass plants in the first three cuts of the two growing seasons • Whereas, the effect of the applied micronutrients on the height of Egyptian clover was fluctuating among cuts and growing seasons having no specific trend • D - Leaf/stem ratio (17) Leaf/stem ratio of Egyptian clover was continuously and significantly increased by applying the subsequent increments of N levels ( 0 to 90 kg/fad) in the first and second cuts • Whereas, the third and fourth cuts were differently affected • Regarding the two studied cuts of ryegrass, there was a significant and continuous increase in leaf/stem ratio as the N application level increased from 0 to 90 kg/fad. This increase was significant in the third cut but not in the fourth one of the two growing seasons • (18) Results did not show any’ significant effect for the applied micTonutrients , concentrations or their interaction on leaf/stem ratios of either Egyptian clover or ryegrass in the mixture • E - Leaf area : (19) Nitrogen levels up to 60 kg/fad is the sufficient dose that is required for producing high leaf area of Egyptian clover and . ryegrass in the mixture • These results were reflected on either forage or dry yield that previously discussed • (20) Micronutrients did notsignific~nt1y affect leaf area of Egyptian cloVer in all cuts of the two growing seasons • This was not the case for ryegrass where leaf area was significantly affected by the applied micronutrient treatments in the first three cuts of the two growing seasons. Manganese ranked the first in producing the highest leaf area of ryegrass with a significant difference compared with each of the other micronutrients • No significant effects for the various concentrations of the applied micronutrients w,ere obtained. . F - Number of tillers/~egrass plant in t4e mixture (21) Applying 60 kg N/fad 1s the optimum level for producing the maximum number of tillers per plant under the circumstances of these experiments • Th:is N level appeared to be the suggested level for producing the maximum forage ~nd dry yield of the mixture • The heighest number of tillers per ryegrass plant was prod~ced in the middle two cuts (22) Neither the applied micronutrients , concentrations or the interaction of both exhibited any significant·effect on the number ... c. j, of tillers/plant . However, Mn at its highest concentration 0.4% looks to have the highest effect in increasing the number of ryegrass tillers per plant • G - Botanical c~osition of the mixed stand : (23) Ryegrass and weeds fractions of the mixed stand were increased and Egyptian clover was decreased as the N application level increased from 0 up to 90 kg/fad. (24) No specific effect for either micronutrients , concentrations or their interaction on the botanical composition of the mixed stand was obtained ., H - Light intensity: (25) The highest realistic increase in the amount of light that penetrated and intercepted by the plant canopies was at 60 kg N/fad with a continuous significant increase as the N levels increased from 0 and up to ’this level. (26) Manganese at the concentration of 0.4% , and Zn at 0.1% sigpificantly produced less light intensity on the ground surface as compared to the control. Whereas, no significant interaction· effect was detected between the different applied micronutrients and their concentrations • I - Chlorophyll pigments content : (27) Nitrogen application level.up to 90 kg/fad significantly increased chlorophyll a , b and carotenoides in both Egyptian clover and ryegrass leaves in the mixed stand • (28). Zinc ,Cu or Fe were the most potent micronutrients that played a role in promoting the accumulation of chlorophyll pigments and carotenoides in Egyptian clover or ryegrass in the mixed stand • (29) The highest accumulation of chlorophyll a ,b and carotenoides in Egyptian clover were obtained by applying 90 kg N/fad with Zn at 0.2 % for either chlorophyll a or b , and with Fe at 0.4 % for carotenoides • In ryegrass, 90 kg N/fad with Cu at 0.2% produced the highest chlorophyll a , band carotenoides • J - Crude protein content and y~eld : (30) Applying 60 kg N/fad increased the crude protein content of the mixture compared with the control by 8.57 , 6.77 , 5.57 and 8.07 % in the subsequent four cuts , respectively , being 30.0 , 35.8 , . 20.8 and 23.2 % for crude protein yield(31) Manganese 0.4 % produced the highest crude protein content and yield of the mixture K - Crude fiber content and yield : (32) Crude fiber content significantly decreased as N application level increased from 0 to 90 kg N/fad. Whereas, nitrogen application increased the crude fiber yield of the mixed forage stand. (33) No significant effect was detected for the various micronutrient treatments on crude fiber content • Whereas , the crude fiber yield was Significantly affected by the applied micronutrients • the lowest crude fiber yield and Zn or Cu were in between • Manganese produced the highest crude fiber yield while Fe produced L - Total carbohYdrates ( CH20 ) content and yield : (34) The lowest CH20 content was obtained at the highest N application level and the reverse was true • Whereas , the total CH 2 ti yield responded differently to the applied N levels compared with the (35) Manganese significantly produced the highest CH 2 0 yield compared to Fe which produced the lowest CH 2 0 yield • M - Fat content : (36) There wa.s no specific trend for the effect of the applied treatments on fat content of the forage mixture • N - Ash content (37) Ash content increased by the subsequent increase in N application level up to 90 kg N/fad in the first three cuts and up to 60 kg N/fad in the fourth cut • (38) Manganese was the most potent element among the other applied micronutrients in producing the highest ash content • And Zn ranked the second after Mn with no significant differences between Mn and Zn in their effect on ash content of the forage mixture. o - Zinc content : ~ (39) The application of 0.2 % Zn with 90 Kg N/fad accumulated the highest Zn content • p - Iron content : (40) The application of 0.4 % Fe with 90 kg N/fad accumulated the highest Fe content in the mixture • Q - Manganese content : (41) The application of 0,4 % Mn with 90 kg N/fad accumulated the bj,ghest MIl content in the forage mixture , R - Copper content: (42) The application of 0.2% Cu with 90 kg N/fad accumulated the highest Cu content s - Dry matter disappearance : (43) The highest DMD % was obtained by applying Mh at 90 kg N/fad. |