00000caa a22000003i 4500 UP-1685594773861817116 Buklod 20230619085743.0 j|||||||||||||| | ta 160921s1987 xx r |||| u|eng d (iLib)UPBAG-00008224633 Circulation-Monograph Tivy, Joy author. Nutrient cycling in agro-ecosystems Joy Tivy. 1987. pages [93]-113 illustrations 28 cm Photocopy. Includes bibliographical references (pages 111-113). The nutrient cycle in the unmanaged ecosystem is compared with that in the agroecosystem; and the role and relative importance of soil organic matter, organic and inorganic fertilizers as sources of nutrient inputs into agro-ecosystems are analysed. This is followed by an assessment of the efficiency with which nitrogen, phosphorus, potassium, liming bases and micro-nutrients are cycled in agroecosystems. Finally, the characteristics of nutrient budgets and nutrient cycles in extensive, intensive and intermediate agro-ecosystems are summarized and the environmental implications of the very open agro-ecosystem noted. Fertilizers. Nutrient cycles. Cropping systems Environmental aspects. Applied Geography (April 1987) : pages 93-113. Vol. 7, No. 2. FO UPBAG UPBAG-MAIN Circulation-Monograph Analytics