Titlebook: Nitrogen Cycling in Ecosystems of Latin America and the Caribbean; G. P. Robertson,R. Herrera,T. Rosswall Book 1982 Martinus Nijhoff/Dr W.

ODIUM

Nitrogen distribution in several traditional agro-ecosystems in the humid tropical lowlands of sout polyculture, manioc (yuca, cassava), taro (malanga), and upland rice. Total biomass and nitrogen content were determined monthly for standing live, standing dead, and litter biomass of both crop and non-crop components of each system. The crop component was further divided into roots, crown, stem,

GEN

马笼头

15N-urea transport and transformation in two deforested Amazonian soils under laboratory conditionsherefore an urgent need to better understand the conditions and characteristics of the soils of that region. In this study a Red Yellow Podzol and a Yellow Latosol were used to examine urea transport and transformation in the laboratory under water-saturated conditions. The soils were collected in a

daredevil

Nitrogen cycling in sugarcane,tarted in the 1940’s with applications of sodium nitrate, and little yield improvement was obtained in most cases. Average yield is around 70 t ha. yr. (4-harvest mean), with the first harvest 1.5 year from planting and a ratoon harvest each year thereafter. Nitrogen responses are obtained only with

tooth-decay

Nitrogen gains and losses in sugarcane (, sp.) agro-ecosystems on the coast of Peru,o the system . irrigation water from rivers and deep wells. 1.2% of the total N in the soil is in available form during the growing season. N extracted by the aerial part of the plants ranges from 210–246 kg N ha. crop.; .. 70% of this is removed in the harvest, and most of the remainder is lost . p

驾驶

Potential growth of alfalfa (, L.) in the desert of Southern Peru and its response to high NPK fertthe summer period and of 150 kg ha. d. during winter. These high rates were maintained for 10 to 20 days, after which growth rates declined. ‘Ceiling’ yields of about 5000 kg dry forage ha. in summer and 3500 kg ha. in winter were obtained in a growth period of 53 days. Simulations with an adapted m

SPASM

Indecisive

侵蚀

LANCE