This study aimed to evaluate the morphophysiological characteristics of irrigated Pennisetum purpureum cv. Cameroon subjected to doses of an organic compost from waste generated by production and slaughter of small ruminants. The experiment was carried out in a grassland, during four growth cycles of 60 days. The area is located in the Embrapa Caprinos e Ovinos unit, in Sobral -CE, Brazil. Treatments consisted of organic compost doses (0, 13.3, 26.6, 39.9, 53.2 and 79.8 Mg ha -1 ) plus a mineral fertilization (nitrogen and potassium) at doses equivalent to 720 and 900 kg ha -1 year -1 , respectively. The experimental design was arranged in completely randomized blocks, totaling four blocks with seven treatments each, in a split plot scheme with repeated readings over time. The plots corresponded to seven doses of an organic compost and an additional treatment (mineral fertilizer), and subplots to four growth cycles. The variables analyzed were total herbage biomass (THB), canopy height (CH), tiller population density (TPD) and water use efficiency for green leaf biomass production (WUE GLB ) and green stem biomass (WUE GSB ). In the first cycle, TPD decreased linearly with increasing doses of the compost, with 47 tillers m 2 at the dose of 79.
ResumoObjetivou-se avaliar as características estruturais do Pennisetum purpureum cv. Cameroon, irrigado e submetido a doses de composto orgânico proveniente de resíduos da produção e do abate da ovinocaprinocultura. O experimento foi realizado em capineira de capim-elefante, durante quatro ciclos de 60 dias cada, em Sobral, Estado do Ceará. Os tratamentos foram as doses do composto orgânico (0; 13,3; 26,6; 39,9; 53,2; 79,8 Mg ha -1 ) e um tratamento mineral (nitrogênio e potássio), equivalente a 720 e 900 kg ha -1 ano -1 . Utilizou-se o delineamento em blocos completos casualizados em esquema de parcelas subdivididas, com leituras repetidas no tempo, onde as parcelas constituíram as doses do composto e os ciclos de crescimento da gramínea, as subparcelas. As variáveis analisadas foram: biomassa total de forragem total (BTF), altura do dossel (ALT), densidade populacional de perfilhos (DPP) e eficiência de uso da água para produção de lâmina (EUA LV ) e de colmo (EUA CV