Kebutuhan Air dan Kalium pada Tingkatan Kemasaman Tanah Berpengaruh terhadap Pertumbuhan dan Produksi Tanaman Peleng (Spinacia oleracea L.A)

Abstract

The research was conducted in te plastichouse a Experimental Garden of Pertapaan Village, Sigalingging Dairi Regency. The location has flat topography approximately 1400 above sea level. The research was carried out since January untill May 2006.

The research intended to know the optimal required water and dosage of Potassium a different soil acidity for maximum growth and production of Spinacia oleracea L.A

The experimental design useed in the research was Complete Randomized Design whereas the treatment design consist of three factors: the Required Water (A) with 3 treatment eves: 300,400, and 500 mm/season; the Potassium Dosage (K) with 4 treatment levels: 0, 60, 120, and 180 kgs K2O/ha and the Soil Acidity (D) with 4 treatment levels of pH 5.5: 6.0: 6.5; and 7.0. The collected data were the plan height (cm), the leaves number, the leaf area (cm2), wet and dry plant weight (g), net assimilation rate (mg.m-2. day). lowering age (days) and plant potassam absorption

It was found that the effect of the required water (A) an dosage of potassium (K) on the height of plant showed a positive by linear regresion except at the age of 40 days after planting (d.a.p.) of treatment with the water which was larger than 400 Mm/season has shown a positive by quadratic regression with the maximum effect at 200 kgs K2O/ha. With the increased application of water, the effect of potassium also increased with the increased dosage of potassium. Whereas the effect of the required water (A) and soil acidity (D), in general, the response curve were a positive by linear, it could be explained that due to higher pH, the elements generally are more easily solvable, therefore, with the sufficient water, the absorption by plant also increases by therefore the growth also better as well. The effect of interaction between the dosage of potassium and the soil acidity (D), the response curve generally indicate a positive by linear and partly a positive by quadratic with the maximum achieved at is it over 6.5. It can be described that the growth increases with the higher pH and amount of potassium. It is in agree equivalent to that of fertilizer.org (2005) that recommended the application of fertilizer of potassium ranging 150 to 180 kgs K2O/ha

The conclution that can be drawn is that: the required water equivalent to 500 mm/season result the better growth and production and the dosage of potassium more than 180 kgs K2O/ha and the increased pH of soil up to 7.0 increases in the growth and production of Spinacia oleracea L.A. The general conclution showed that the treatment still not optimal so that it may be said that the required water, dosage of potassium and acidity rate of soil still have to be found.