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Whitbread Anthony Blair Graeme Naklang Kunnika Lefroy Rod Wonprasaid Sodchol Konboon Yothin Suriya-arunroj Duangjai 《Plant and Soil》1999,207(1):29-36
The maintenance of soil organic matter (SOM) and the balancing of nutrient flows into and out of the rainfed rice cropping
systems in Northeast Thailand is of paramount importance to arresting the decline in soil fertility and crop yields. A system
where small applications of leaf litters from locally grown trees are applied annually to rice paddy soils prior to transplanting
is described. The annual application of 1500 kg/ha of Cajanus cajan, Acacia auriculiformis, Phyllanthus taxodifolius and Samanea
saman for five seasons resulted in increases in rice grain yield of 48, 35, 32 and 23% above the no-leaf litter control, respectively.
Average annual nutrient inputs from the leaf litters, in kg/ha, ranged from 62.7 N, 3.9 P, 17.9 K, and 3.5 S for Cajanus cajan
to 24.5 N, 1.5 P, 8.1 K and 2.0 S for Acacia auriculiformis. Nutrient balances, determined by the difference between the inputs
(fertiliser and added leaf litters) and outputs (grain and straw) indicated net positive N and P balances of up to 457 and
60 kg/ha. respectively, after five seasons of leaf litter applications. Sulfur and potassium balances resulted in net deficits
of up to −3 and −52 kg S and K/ha, respectively, where no leaf litter was applied and rice straw was removed following harvest.
Calculated apparent nutrient recoveries reflected the decomposition rate of the added residues and were highest for P and
K, reflecting their higher soil residual value than mobile nutrients such as N and S. Sustainable farming systems will require
that crop yields are stable through the maintenance of soil fertility and the balance of nutrients in the system.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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