基肥配比和拔节期追氮对糯玉米淀粉糊化特性的影响

为明确糯玉米淀粉糊化特性在不同肥料处理下的变化, 从而改良淀粉的糊化特性, 以糯玉米品种苏玉糯4号为材料, 采用二因素裂区设计, 研究了不同基肥处理(纯N 75 kg hm^-2、纯N 75 kg hm^-2 + K₂O 70 kg hm^-2、纯N 75 kg hm^-2 + P₂O₅ 65 kg hm^-2和纯N 75 kg hm^-2 + P₂O₅ 65 kg hm^-2 + K₂O 70 kg hm^-2)和拔节期追氮(0、150和300 kg hm^-2)对糯玉米淀粉糊化特性的影响。结果表明, 和仅基施氮相比, 增施磷或(和)钾可显著降低峰值黏度和崩解值, 提高谷值黏度、终值黏度和回复值。随着拔节期追氮量的增加, 峰值黏度、谷值黏度、终值黏度逐渐升高, 回复值先升后降, 而崩解值在追施氮150 kg hm^-2和300 kg hm^-2时无显著差异, 但均大于不施追肥处理。峰值黏度与谷值黏度、终值黏度、崩解值极显著正相关(相关系数分别为0.80**、0.87**和0.75**), 糊化温度与峰值黏度、谷值黏度和终值黏度显著负相关(相关系数分别为-0.65*、-0.62*和-0.60*)。在适宜基肥的基础上, 增加拔节期追氮量, 可以改良淀粉的糊化特性。在不同肥料处理中, 基施氮或氮磷并拔节期追施纯氮300 kg hm^-2及平衡基施氮磷钾并拔节期追施纯氮150 kg hm^-2时, RVA谱特征值较为理想(峰值黏度最高且回复值较低)。

Effects of Basic Fertilizer Treatments and Nitrogen Topdressing at Joint- ing Stage on Starch RVA Characteristics of Waxy Maize

Proper fertilizer managements can improve the starch pasting properties of waxy maize (Zea mays L. Ceratina Kulesh). To understand the starch Rapid Visco Analyzer (RVA) characteristics of waxy maize, we used Suyunuo 4 in a field experiment with different treatments of basic and topdressing fertilizers, especially the N fertilizer. The split design was employed with main plot of 4 basic fertilizer treatments (N 75 kg ha^-1, N 75 kg ha^-1 + K₂O 70 kg ha^-1, N 75 kg ha^-1 + P₂O₅ 65 kg ha^-1, and N 75 kg ha^-1 + P₂O₅ 65 kg ha^-1 + K₂O 70 kg ha^-1) and split plot of 3 N topdressing treatments (N 0, 150, and 300 kg ha^-1). The peak viscosity (PV), trough viscosity (TV), final viscosity (FV), breakdown (BD), and setback (SB) varied in different fertilizer treatments except peak time (PT) and pasting temperature (PTP). Compared with the treatment of only N applied in basic fertilizer, adding P or (and) K fertilizers decreased the PV and BD, but increased TV, FV, and SB. With larger amount of N topdressing at jointing stage, PV, TV, and FV increased gradually, SB rose first and fell later. BD showed no significant differences in treatments of top-dressing N 150 and 300 kg ha^-1. Among the RVA characteristics, PV was positively correlated with TV, FV, and BD (r = 0.80, 0.87, and 0.75, respectively, P<0.01), while PTP negatively correlated with PV, TV, and FV (r = -0.65, -0.62, and -0.60, respec-tively, P<0.05). The RVA characteristics of waxy maize starch were improved to be the better when the top dressing was N 300 kg ha^-1 at jointing stage on the basis of N 75 kg ha^-1 or N 75 kg ha^-1 + P₂O₅ 65 kg ha^-1 as the basic fertilizer, and the top dressing was N 150 kg ha^-1 at jointing stage on the basis of N 75 kg ha^-1 + P₂O₅ 65 kg ha^-1 + K₂O 70 kg ha^-1 as the basic fertilizer.