Influence of tillage practices and fertilization on crop yields and soil properties in long-term crop rotation (soybean-wheat-maize) experiments
Ailincai, C.; Jitareanu, G.; Bucur, D.; Mercus, A.
Journal of Food, Agriculture and Environment 9(1): 285-289
2011
ISSN/ISBN: 1459-0263 Accession: 066242807
The experiments were conducted during 1998-2010 to evaluate the effect of various tillage practices on yield of wheat and maize in a 3-year crop rotation (soybean-wheat-maize) and soil chemical and physical properties. Experiments were set up in split-split plots on a typical Cambic Chernozem of clay-loam texture, mean humus content (3.3%), weakly acid reaction and mean supply in mineral elements. After 13 years of experiments, ploughing at a depth of 20 cm resulted in settling the soil layer at the depth of 19-26 cm, causing the increase in apparent density at 1.52 g.cm(-3), the decrease in total porosity at 43.3% and the increase in settling degree until 16.4% of the volume. In case of chisel tillage, apparent density decreased from 1.41 to 1.33 g.cm(-3), settling degree diminished at 0.8% and hydraulic conductivity increased from 6.4 to 21.5 mm.h.(-1) at the depth of 40 cm. The mean wheat yield obtained during 1998-2010 was 3265 kg.ha(-1) at 20 cm ploughing, 3521 kg.ha(-1) at 30 cm ploughing, 3143 kg.ha(-1) at chisel and disk till and 3042 kg.ha(-1) in case of soil treatment by repeated disking. The mean wheat yield was 1818 kg.ha(-1) under unfertilized, 3532 kg.ha(-1) at rate of N(120)+80 kg.ha(-1) P(2)O(5) and 3940 kg.ha(-1) at rate of N(80) + 80 kg.ha(-1) P(2)O(5) + 30 t.ha(-1) manure. The fertilizer application resulted in gaining yield increases between 59% (1071 kg.ha(-1)) at rates of N(80) + 80 kg.ha(-1) P(2)O(5) + 6 t.ha(-1) hashed straw and 117% (2122 kg.ha(-1)) at rates of N(80) + 80 kg.ha(-1) P(2)O(5) + 30 t.ha(-1) manure. The paper presented the results of investigations concerning the influence of long-term fertilization on some chemical characteristics of soil and on the wheat and maize yields. On slope lands, the high rate fertilization of maize crop (N(140)P(100)) in the latest 13 years, gave an average yield increase of 103% (3373 kg.ha(-1)), against control, and applying a rate of N(70)P(70)+40 t.ha(-1) manure resulted in very close yield increase (99%, 3258 kg.ha(-1)). The total carbon content in soil had significant increases at rates higher than N(140)P(100) and in case of organo-mineral fertilization. The annual fertilization of wheat and maize, at the rate of 70 kg N + 70 kg P(2)O(5)center dot ha(-1) + 6 t.ha(-1) stalks of wheat, compared to the unfertilized variant gave an increase in the content of soil organic carbon by 14.5% (2.4 g organic C.ha(-1)) on weakly eroded soils and by 29.5% (4.2 g organic C.ha(-1)) on highly eroded soils. During the long-term fertilizing of wheat and maize with high rates of mineral fertilizers (N(140)P(100)) on highly eroded lands the total content of carbon increased by 16.9% (2.4 g organic C.ha(-1) soil), against the unfertilized control.