POSSIBILITY OF REPEFED GROWTH OF ALFAALFA ON PSEUDOGLAY

Accepting the known advantage of lucerne, both in the biological and agrotechnical respect, an 8-year experiment with lucerne was carried out in two phases. In the first phase, that is rotation, investigations covered the introduction of lucerne onto pseudogley, while in the second phase the possibilities were investigated of its repeated growing, as a further step in the complex consideration of the up-to-date agrotechnical and other problems in the growing of lucerne. In this connection, special attention was paid to the description of the climatic and edaphic characteristics of the region in which the experiment was laid out. The results of the first rotation of the experiment are presented in Table 1, and those of the second rotation in Tables 2 and 3. The results of the introduction of lucerne onto pseudogley, though only partially in this paper, show that, through application of certain agrotechnical practices, it is possible to introduce lucerne onto this soil type and that this measure presents a significant new quality in raising the production capacity of pseudogley to a higher level. The results also show that deep ploughing and mineral fertilizing, without application of organic fertilizers, are capable of preparing a substratum suitable for lucerne growing and that this development path of agrotechnical amelioration of pseudogley is not only shorter in time but also considerably cheaper in comparison with gradual deepening of the soil and cation of organic fertilizers. In the first rotation, fertilizing was fully expressed, even ensuring a mean 5-year hay yield over 100 q/ha. In this respect, besides phosphorus and potassium, a significant part was played by boron and molybdenum, while liming was less justifiable. The successful completion of the first investigation phase created the basis for embarking upon the second phase, i. e. the investigation of possibilities of the repeated growing of lucerne, keeping in mind the early withering of lucerne and its intolerance to the repeated growing, related to the phenomenon of „soil fatigue“. As the introduction of lucerne to pseudogley is in itself a relatively costly practice (ploughing at the depth of 60 cm), one of the aims of investigating the possibilities of its repeated growing was to determine if the same productivity level can be maintained by less intensive agrotechnical practices (ploughing at the depths of 20 and 30 cm), as a compensation for the first rotation. Also here good results were obtained. Still, it is our opinion that the investigations of the repeated growing of lucerne should be continued in different ecological conditions, including also the other aspects of this problem