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Effects Of Fertilization And Tillage On Dynamic Change Of Soil Water,C,N And P In Newly-built Terraces

Posted on:2016-06-05Degree:MasterType:Thesis
Country:ChinaCandidate:J T LiFull Text:PDF
GTID:2283330461477558Subject:Ecology
Abstract/Summary:PDF Full Text Request
Water is the main factor influencing crop yield in dryland areas, and the efficient way to increase crop yield is to improve utilization efficiency of precipitation. Terraces can increase the amount of rainfall infiltration, reduce runoff, and control soil erosion, so the terraces are promoted in the loess plateau region. Low soil fertility, low microbial activity, and low crop yield are the characteristics of newly built terraces.So we established an experiment to explore the optimum method for improving soil fertility and crop yields in newly built terraces.Twelve treatments were established in the experiment:(1) CK:flat plot neither mulched with plastic film nor applying fertilizers; (2) ANP:flat plot applying nitrogen ang phosphorus fertilizer; (3) AMNP:flat plot applying sheep manure and nitrogen and phosphorus fertilizer; (4) ASNP:flat plot applying maize straw and nitrogen and phosphorus fertilizer; (5)BNP:double ridges and furrows mulched with plastic film and applying nitrogen and phosphorus fertilizer; (6) BMNP: double ridges and furrows mulched with plastic film and applying dung and nitrogen and phosphorus fertilizer; (7) BSNP:double ridges and furrows mulched with plastic film and applying maize straw and nitrogen and phosphorus fertilizer; (8) B2SNP:double ridges and furrows mulched with plastic film and applying 2 times (maize straw and nitrogen and phosphorus fertilizer); (9) CNP:groove ridge is mulched with plastic film only applying nitrogen and phosphorus fertilizer; (10) CMNP:double ridges and furrows mulched with plastic film and applying sheep manure and nitrogen and phosphorus fertilizer; (11) CSNP:double ridges and furrows mulched with plastic film and applying straw and nitrogen and phosphorus fertilizer; (12) C2SNP:double ridges and furrows mulched with plastic film and applying 2 times (maize straw and nitrogen and phosphorus fertilizer). Four kinds of fertilization pattern:the inputs of nitrogen and phosphorus are consistent in NP and MNP and SNP treatment, the total mass of organic carbon inputs are consistent in MNP and SNP treatment, the total mass of carbon and nitrogen and phosphorus inputs in 2SNPS treatment are twice of the SNP treatment. The terrace was modified from slope land in 2011 and the experiment began in April 2013.For newly built terraces, concerning about the organic carbon in 0~30 cm soil, we get the following results:Compared October 2014 with April 2013, the content of organic carbon in 0~30 cm soil, CK, ANP, BNP and CNP did not change significantly, while other treatments increased significantly. In addition, AMNP, ASNP, BMNP, BSNP, B2SNP, CMNP, CSNP and C2SNP increased about 1.75, 2.59,1.31,3.54,1.61,3.10,1.22 and 2.68 g / Kg respectively, BSNP increased the most for the content of organic carbon in soil.From October 2013 to October 2014, the content of organic carbon in 0~30 cm soil, CK, ANP and AMNP was not change significantly, application of nitrogen and phosphorus fertilizers separately or application of sheep manure and nitrogen and phosphorus fertilizers together will not change the content of organic carbon in soil within two years significantly. In October 2014, ASNP was higher than CK, ANP and AMNP about 1.04,1.92 and 1.84 g / Kg respectively. In the situation of non-covered flat plot, application of corn stalks and nitrogen and phosphorus fertilizers together increased the content of organic carbon in soil the most significantly.From October 2013 to October 2014, BSNP always higher than BNP, BMNP and B2SNP, In October 2014, BSNP higher than BNP, BMNP and B2SNP about 3.24,2.23 and 1.93 g / Kg respectively. In the case of non-covered ridges and furrows, application of 2 times corn stalk and 2 times nitrogen and phosphorus fertilizer can’t increase the content of organic carbon in soil doubled similarly.In October 2014, CMNP> C2SNP> CSNP> CNP, the contents about 6.26,5.85,4.39 and 2.99 g / Kg respectively. Moreover, CMNP and C2SNP have no significant difference, while other treatments was difference significantly. In the case of covered ridges and furrows, application of sheep and nitrogen, phosphorus fertilizers together to increase the content of organic carbon in soil was better than the other three methods of fertilizations. Compared October 2014 with April 2013, CSNP and C2SNP increased about 1.22 and 2.68g / Kg respectively, close to 1:2. In the case of covered ridges and furrow, application of the 2 times corn stalks and 2 times nitrogen, phosphorus fertilizers increased the amount of organic carbon in soil doubled.From October 2013 to October 2014, ANP> BNP> CNP. In October 2013 and October 2014, ANP was higher than CNP significantly, and higher about 1.02 and 0.84 g / Kg respectively. In the case of applying with nitrogen, phosphorus fertilizers, when non-covered ridges and furrow compared with non-covered flat plot, the results showed that no significant effect on accumulation of organic carbon in soil within two years. While covered ridge and furrow compared with non-covered flat plot, was not suit for the accumulation of organic carbon in soil.From October 2013 to October 2014, the difference of AMNP and CMNP was not always significant, BMNP was always lower than AMNP and BMNP. In October 2014, the treatment of BMNP was significantly lower than CMNP about 1.79 g / Kg. In the case of application of sheep and nitrogen, phosphorus fertilizers, no-covered ridge and furrow was not conducive for the accumulation of organic carbon in soil, while covered ridge and furrow compared with non-covered ridge and furrow was no significant effect on accumulation of organic carbon in soil within two years.From October 2013 to October 2014, BSNP> ASNP> CSNP, BSNP was always higher than CSNP significantly, and in October 2014, higher about 2.31 g / Kg. B2SNP and C2SNP was always no significant difference. In the case of application of corn stalk and nitrogen, phosphorus fertilizer, covered ridge and furrow is not conducive for the accumulation of organic carbon in soil, while non-covered ridge and furrow compared with non-covered flat plot was no significant effect on accumulation of organic carbon in soil within two years.B2SNP and C2SNP is always no significant difference, so in the case of application of 2 times corn stalk and 2 times nitrogen, phosphorus fertilizers, the ridge and furrow compared with non-covered ridge and furrow was no significant effect on accumulation of organic carbon in soil within two years.In 2013, the biomass of maize aboveground under the same methods of fertilization, showed the highest in covered ridge and furrow, and higher than the non-covered ridge and furrow significantly. In the treatment of non-covered flat plot and non-covered ridge and furrow, the biomass of maize aboveground under the same farming methods, application of straw and nitrogen, phosphorus fertilizers were higher than other treatments significantly. In the treatment of covered ridge and furrow, the biomass of maize aboveground in CMNP and CSNP was higher than the CNP and C2SNP significantly.In summary, the methods of sheep, corn stalk, ridge and furrow and covered terraces will influence the content of organic carbon in 0~30cm new soil, while applying for nitrogen, phosphorus fertilizers had no significant effect on organic carbon in soil within two years. Among of the 12 treatments, the treatment of BSNP is best for enhancing the effect of organic carbon in soil. In the case of non- covered flat plot, ridge and furrow, the straw is more effective than sheep; in the case of covered ridge and furrow, sheep is more effective than straw. In the same methods of fertilization, non-covered ridge and furrow compared with non-covered flat plot was almost no effect. Covered ridge and furrow may not be conducive for accumulation of organic carbon in soil with the application of straw, but can promote the decomposition of sheep, to accelerate the accumulation of organic carbon in soil. In the case of application of straw, covered ridge and furrow will cause a certain antagonism for accumulation of organic carbon; in the case of application of sheep manure, covered ridge and furrow has a certain synergy for accumulation of organic carbon. In the case of non-covered ridges and furrow, application of 2 times corn stalks and 2 times nitrogen, phosphorus fertilizer is not conducive for the accumulation of content of organic carbon in soil. And in case of covered ridge and furrow, application of 2 times corn stalks and 2 times nitrogen, phosphorus fertilizers will increase the organic carbon in soil doubled.Therefore, it is possible for a new built terraced fields to take a rest about one year, and in the case of non-covered ridge and furrow, the methods of application of corn stalks and nitrogen can enhance the content of organic carbon in soil, and to improve the soil. While for the planting crops, and in the case of covered ridge and furrow, the methods of application of sheep and nitrogen, phosphorus fertilizers is most beneficial to improve crop yield and the content of organic carbon in soil.
Keywords/Search Tags:Semiarid Loess Plateau, Newly built terraces, Double ridges and furrows, Soil organic carbon, Soil moisture
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