摘要
【目的】研究长期秸秆还田与施肥对作物产量和土壤肥力的影响,为该种植模式下作物最佳养分管理提供技术支撑。【方法】自2005年起在成都平原的广汉市开展了水稻-油菜轮作下连续秸秆覆盖还田+免耕与不同施肥的长期定位试验。试验为随机区组设计,共有8个处理,3次重复。这8个处理包括对照(只施化肥、无秸秆覆盖)和秸秆覆盖还田下4个氮肥用量、2个磷肥用量和3个钾肥用量的7个组合处理。自2005年起每季收获时采集植株样本,分析不同处理下水稻和油菜的农艺形状与产量变化情况,2010年水稻收获后采取耕层(0—5 cm、5—15cm和15—30 cm)土样,分析不同处理的土壤肥力演化趋势。【结果】在稻-油轮作下,同一处理水稻和油菜产量受气候变化影响存在显著的年度间差异。秸秆还田对水稻产量的影响始于覆盖后的第三年,即秸秆覆盖处理的水稻产量显著高于相同施氮量的无覆盖对照处理,油菜秸秆覆盖条件下的减磷和减钾处理的水稻产量相当或高于对照处理。按此计算,秸秆还田在水稻季每公顷可节约大约N 60 kg和K2O 90 kg。在油菜季,稻草覆盖似乎不能明显减少氮肥投入,减磷处理的油菜产量始终最低。因此,施用充足的磷肥成为油菜高产的关键,该结果为稻-油轮作制度中磷肥的合理分配提供了科学依据,即磷肥应重点施在油菜上,水稻上可少施或不施磷肥。在油菜季,秸秆还田每公顷能节约大约N 30 kg和K2O 90 kg。连续秸秆覆盖+免耕使土壤有机质和氮、磷、钾养分在0—5 cm土层聚集,但对下层土壤影响不大;减磷、减钾处理使土壤磷、钾耗竭,但无覆盖对照处理的土壤钾耗竭大于减钾处理;在磷钾施肥量不变的情况下,增加氮肥施用量降低了土壤速效钾与有效磷含量。长期秸秆覆盖还田+免耕能显著改善0—5 cm土层的土壤物理性状,即降低土壤容重,增加孔隙度、非水稳性和水稳性团聚体的数量,但增加了下层土壤的容重和降低了土壤孔隙度。【结论】长期秸秆覆盖还田+免耕能显著提高水稻-油菜轮作下的作物产量,减少肥料投入和提高表层土壤肥力水平,但油菜季必须注意施用足够的磷肥以保证油菜籽高产的需要。
Objectives]The study of the effects of 1ong-term returning of croP residues and ferti1ization on croP yie1ds and soi1 ferti1ity can offer the scientific base for the best nutrient management in croPPing system.[Methods]A 1ong-term fie1d exPeriment with rice-raPessed rotation has been conducted in Guanghan City, Chengdu P1ain since 2005. The exPeriment consisted of eight treatments:chemica1 ferti1izers without straw mu1ch (CK),four rates of nitrogen,two rates of PhosPhorus and three rates of Potassium under straw mu1ch, resPective1y. Since 2005,P1ant samP1es of each P1ot were co11ected and croP seed/grain yie1ds were recorded at harvest,soi1 samP1es were co11ected at 0-5,5-15 and 15-30 cm dePths of each P1ot after rice harvested in 2010.[Results]Under rice-raPeseed rotation,croP yie1ds vary considerab1y from year to year due to the weather changes. Rice yie1ds were significant1y affected by the surface mu1ched raPeseed residue since the third year of the exPeriment. The rice yie1d of the treatments with the straw mu1ch was significant1y higher than those treatments receiving equa1 amount of N ferti1izer without mu1ch,and equiva1ent or even higher rice yie1ds were obtained in treatments of -P and -K with mu1ch than the CK. Thus,about 60 kg of N and 90 kg of K2 O Per hectare cou1d be cut off from the ferti1izer inPut through raPeseed residue mu1ch in the rice season. In the raPeseed season,however, rice straw mu1ch was not ab1e to reduce nitrogen inPut,the -P treatment Produced the 1owest raPeseed yie1d, indicating that P ferti1izers shou1d be aPP1ied in the raPeseed season,but 1ess or not in the rice season. In the raPeseed season,about 30 kg of N and 90 kg of K2 O Per hectare can be saved by rice straw mu1ch. Continued straw mu1ch and no-ti11age main1y benefit the accumu1ation of soi1 organic matter,N,P and K at 0-5 cm soi1 1ayer, much 1ess in the soi1 1ayers be1ow. The -P and -K treatments obvious1y deP1eted the soi1 P and K reserves and the CK treatment main1y deP1eted soi1 K reserves. Under the same P and K rates,contents of soi1 avai1ab1e K and P were decreased with the increase of N inPut rates. Long-term straw mu1ch and no-ti11age dramatica11y decreased soi1 bu1k density,increased soi1 Porosity,non water-stab1e aggregates and water-stab1e aggregates,imProved the Physica1 ProPerties of the 0-5 cm soi1 1ayer.[Conclusions]Long-term straw mu1ch P1us no-ti11age in the rice-raPeseed rotation system cou1d significant1y increase croP yie1ds,reduce ferti1izer inPuts( Particu1ar1y in rice season)and imProve toP 1ayer soi1 ferti1ity. Adequate P ferti1izer shou1d be aPP1ied in raPeseed,1ess or not in rice for high yie1d and high Profit Production.
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2014年第6期1450-1459,共10页
Journal of Plant Nutrition and Fertilizers
基金
国际植物营养研究所研究基金
公益性行业(农业)科研专项(201003016)资助
关键词
秸秆覆盖
长期试验
稻-油轮作
产量
理化性状
straw mulch
long-term experiment
rice-rapeseed rotation
yield
physical and chemical properties
