本试验以“甬优1540”为材料，通过2年的田间重复试验，在头季稻总施纯氮量（225.00kg·hm^-2）不变的前提下，设置头季不同氮肥运筹处理（基肥：第一次分蘖肥：第二次分蘖肥：穗肥比分别为3:1:2:4(N1)、3:2:1:4(N2)、3:3:0:4(N3)、4:3:0:3(N4)），从水稻群体分蘖特性、冠层结构特点、光合生理变化及干物质积累与运转规律入手，探讨了东南稻作区机械化栽培下头季稻氮肥运筹对再生稻产量形成的影响。结果表明，头季前氮后移施肥的N1处理有助于增加头季分蘖数，提高分蘖成穗率，N1处理成穗率高达70.18%，比基蘖肥比重高的当地常规施肥N4处理提高了9.15%。N1处理还有助于提高群体LAI值，其头季及再生季齐穗期LAI值分别比N4处理提高了16.52% 和29.87%。就茎鞘物质运转率及冠层光能截获率而言，N1处理下其头季稻茎鞘物质运转率比N4处理提高了50.57%，而其再生季齐穗期的冠层光能截获率比N4处理提高了5.07%。在本试验中,头季稻前氮后移的N1处理两季实际总产量最高，2年平均实际总产达17351.23 kg·hm^-2，比当地常规施肥N4处理提高了23.00%。由此可见，头季稻合理氮肥处理有利其提高健桩存量，从而为再生季作物的群体及产量形成奠定基础。在本研究中，低留桩机械化栽培下头季稻适当的前氮后移，不仅提高头季稻产量，而且还有利其再生腋芽的萌发，增加再生季成穗率，从而实现水稻一种两收目的。

Conservation tillage may improve yield of cotton in addition to improvement in soil quality if practiced for longer period. However, the practice may not be productive in short-term particularly when severe weeds are infesting the crops such as Cynodon dactylon, Conyza canadensis, Tribulus terrestris, and Cyperus rotundus, etc. Recent studies indicate that conventional tillage (CT) is more productive than zero tillage (ZT)/reduced tillage (RT). Performance of cotton under three tillage systems, viz., ZT, RT and CT; and five herbicides, i.e., haloxyfop-R-methyl 10.8 EC (108 g a.i. ha-1), lactofen 24 EC (168 g a.i. ha-1), haloxyfop 10.8 EC + lactofen 24 EC, hand weeding, and weedy check were evaluated during 2010-2011 at Gomal University, D.I.Khan, Pakistan, to explore the best management option for effective weed control, enhanced yield and quality of cotton grown after wheat. The results revealed that hand weeding and Haloxyfop as post emergence alone or in combination with Lactofen reduced weed density to the minimum irrespective of the tillage systems. Excessive rainfall and cooler temperature limited cotton growth and yield in 2010. The adverse weather conditions had more adverse effect on boll weight under ZT and RT than CT. Haloxyfop + lactofen produced higher seed cotton yield in RT than ZT, however, it could not exceed CT. Broad-spectrum herbicides × CT produced the highest number of bolls/plant, boll weight and seed cotton yield. Fiber quality and net returns were also the highest in broad-spectrum herbicides × CT. In conclusion, broad-spectrum herbicides under CT were more productive in wheat based cropping system on silty clay soil of D.I.Khan.