Effects of Seeding Dates and Growth Periods on the Growth Characteristics, Dry Matter Yield and Feed Value of Corn for Silage in Paddy Field

This study was carried out to investigate the effects of the seeding dates and growth periods on the growth characteristics, dry matter yield and feed value of corn for silage in paddy field. The experimental design was arranged in a randomized block design with three replications. Treatments consisted of five seeding dates, 1 May (T1), 8 May (T2), 15 May (T3), 22 May (T4) and 29 May (T5). And harvesting time homologized by August 24. Therefore, growing periods were 115 days (T1), 108 days (T2), 101 days (T3), 94 days (T4) and 87 days (T5), respectively.　In maturities at harvest time, T1, T2, T3, T4 and T5 were full dent, early dent, late dough, dough and early dough stage, respectively. Plant height and numbers of root system were highest in T5 (p less than 0.01), but leaf length was higher in T4 than others (p less than 0.05). Dead leaf, tip filling degree and ear circle were higher in T1 than others (p less than 0.05, 0.01). Leaf width, ear height, leaf number, ear length, stem diameter, stem hardness and brix were not significantly different among the treatments. Dry matter yield and TDN yield were higher in the order of T1 greater than T2 greater than T3 greater than T4 greater than T5 (p less than 0.01). Crude protein, crude ash, NDF, ADF and crude fiber were significantly higher in T4 (p less than 0.05, 0.01). But crude fat was the highest in T1, T3 was the lowest as compared to other treatments (p less than 0.01). Total EAA (essential amino acids) were higher in order of T4 greater than T3 greater than T1 greater than T2 greater than T5, and total NEAA (nonessential amino acids) were higher in order of T1 greater than T4 greater than T2 greater than T3 greater than T5, and total amino acids were higher in order of T4 greater than T1 greater than T3 greater than T2 greater than T5. But no significant differences were found among the treatments. TUFA(total unsaturated fatty acid) and TSFA(total saturated fatty acid) were in order of T1 greater than T2 greater than T3 greater than T5 greater than T4 (p less than 0.01). Minerals were the highest in T4 (4,721.25 mg/kg), and T2 (2,970.80 mg/kg) was the lowest as compared to other treatments (p less than 0.05). Based on the above results, seeding dates could be recommended as early May, and harvest times is yellow ripe stage for qualitative and quantitative production of corn for silage in rice paddy field soil.