轮耕对渭北旱塬春玉米田土壤理化性状和产量的影响

Effects of rotational tillage on soil physiochemical properties and spring maize yield in Weibei Highlands

为了揭示不同轮耕处理对渭北旱塬春玉米田土壤理化性状及春玉米产量的影响,于2008—2010年在陕西合阳设置了免耕深松免耕(NT/ST/NT)、深松翻耕深松(ST/CT/ST)、翻耕免耕翻耕(CT/NT/CT)、免耕免耕免耕(NT/NT/NT)、深松深松深松(ST/ST/ST)和翻耕翻耕翻耕(CT/CT/CT)6种轮耕模式,测定和分析了各轮耕处理下土壤容重、土壤养分与玉米产量差异。结果表明:(1)各轮耕处理降低了土壤容重,提高了土壤孔隙度,增加了田间持水量,且以NT/ST/NT处理效果最佳;与对照CT/CT/CT相比,NT/ST/NT处理0～20cm和20～40 cm土层土壤容重分别降低11.43%和9.79%,土壤孔隙度分别增加11.05%和9.87%。(2)NT/ST/NT处理对耕层0～20 cm土层土壤有机质和全氮含量影响显著(P<0.05),0～60 cm土层土壤有机质平均含量最高(10.36 g.kg 1),土壤全氮含量平均值比试验开始前和对照CT/CT/CT分别提高10.65%和4.31%;各耕作处理对0～20 cm土层土壤全氮和碱解氮含量影响较大,而对20～40 cm土层土壤有效磷和速效钾含量影响较大,保护性轮耕处理对土壤培肥效应显著(P<0.05)高于传统翻耕处理。(3)NT/ST/NT、ST/CT/ST、CT/NT/CT、NT/NT/NT和ST/ST/ST处理产量比对照CT/CT/CT处理分别增产22.42%、16.33%、3.77%、9.91%和14.18%(P<0.05),以NT/ST/NT处理春玉米增产率最高。

A study was conducted to investigate the effects of different rotational tillage patterns on soil physiochemical properties and spring maize yield.The study consisted of a continuous experiment of spring maize in six rotational tillage treatments conducted in the Weibei Highlands of Heyang County,Shaanxi Province from 2008 to 2010.The tillage treatments included NT/ST/NT（3-year rotational no-tillage,sub-soiling and no-tillage system）,ST/CT/ST（3-year rotational sub-soiling,conventional tillage and sub-soiling rotated system）,CT/NT/CT（3-year rotational conventional tillage,no-tillage and conventional tillage system）,NT/NT/NT（3-year continuous no-tillage system）,ST/ST/ST（3-year continuous sub-soiling system） and CT/CT/CT（3-year continuous conventional tillage system）.Among other parameters,soil bulk density,soil nutrient and spring maize yield under different rotational tillage treatments were measured and analyzed.Compared with CT/CT/CT,conservation tillage significantly（P 〈 0.05） decreased soil bulk density but also enhanced soil total porosity and field capacity.Compared with CT/CT/CT,NT/ST/NT decreased soil bulk density by 11.43% in the 0~20 cm soil layer and 9.79% in the 20~40 cm soil layer.Soil porosity increased by 11.05% and 9.87% respectively in the 0~20 cm and 20~40 cm soil layers under NT/ST/NT treatment.NT/ST/NT had significant effects on soil organic matter and total nitrogen contents in the 0~20 cm soil layer（P 〈 0.05）.Under NT/ST/NT treatment,average soil organic matter content in the 0~60 cm soil layer was the highest（10.36 g？kg？1） for all the treatments.The average total soil nitrogen content under NT/ST/NT treatment increased by 10.65% and 4.31% respectively compared with initial value and CT/CT/CT treatment.Total N and alkali-hydrolyzable-N contents in the 0~20 cm soil layer and available P and K contents in the 20~40 cm soil layer were more significantly affected by different tillage treatments compared with other indexes.Rotational conversation tillage treatments showed significantly higher soil fertility-enhancing effect compared with the conventional tillage.Spring maize yield under NT/ST/NT,ST/CT/ST,CT/NT/CT,NT/NT/NT and ST/ST/ST increased by 22.42%,16.33%,3.77%,9.91% and 14.18%（P 〈 0.05）,respectively,compared with CT/CT/CT.The rate of increase of spring maize yield under NT/ST/NT treatment was the highest among all the treatments.