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Studies on the mineral nutrition of the coffee plant: xl. Biomass and nutrient content on the material removed by pruning

An experiment has carried out in commercial coffee plantation (varie ty Mundo Novo, 7 years old, 1904 "covas" per ha, previous yield 3,180 kg cleancoffe, Ipanema Agro Indústria S.A., Alfenas, MG, Brazil) designed to estimate the quantities of biomass, macro and micronutrients there in, removed by different types of pruning, namely: (1) stumping at 0,40 m above ground;(2) capping at 1,00 m; (3) capping at 1,50 m; (4) capping at 2,00 m; (5) capping at 1,50 m and cutting of laterals at 15 cm from the main stem. Analyses of data and material allowed for the following conclusions to be drawn. (1) Biomass removed by pruning was higher when pruning was done by stumping (24.3 tons of fresh weight and 11.9 tons dry weight) and by capping at 1,00 m above ground (20.6 and 10.1 tons, respectively); these treatments were followed by capping at 1,50 m plus cutting off laterals which yielded 19.4 and 8.3 tons of fresh and dry weight; the fresh and try weight corresponding to capping at 1,50 and 2,00 m above ground were: 12.1 and 5.4, 5.6 and 2.5 tons por hectare. (2) Simple regression equations describe with a high degree of significance the relationship between height of pruning and biomass removed there off. (3) The amount of macro and micronutrients, as expected, relate well with the quantity of plant material which corresponds to each treatment. Total amounts for macronutrients were, according to the order of the treatments given above (in kg/ha): N - 320; 294; 162; 80 and 261; P - 18; 15; 10; 44 and 16; K - 286; 266; 168; 78 and 273; Ca - 149; 139; 63; 33 and 101; Mg - 30; 33; 16; 8 and 26; S - 10; 7; 6; 3 and 10. In the same order, the amounts of micronutrients were, in g/ha: B - 306; 337; 163; 83 and 268; Cu - 229; 219; 121; 51 and 191; Fe - 2783; 2328; 1367; 544 and 2088; Mn - 437; 779; 264; 142 and 412; Zn - 174; 152; 74; 28 and 121. (4) Simple regression equations were derived which express the relationship between quantities of macro and micronutrients removed and the heighth of pruning. (5) Recycling of the biomass curt off fy pruning could contribute to savings in the rates of fertilizer to be applied in the period of regrowth. Most of the nutrients, however, from two thirds to three fourths of the total, are found in branches and stems which is likely to more slonly released.


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