1. The Biblical Melachos:
It is Biblically forbidden to perform any of the following Melachos during [Biblical] Shemitah:
- Seeding [Zeria]
- Harvesting [Ketzira or Betzira]
- Pruning [Zemira]
- Planting [Netia]
2. The Rabbinical Melachos:
It is Rabbinically forbidden to perform any of the following Melachos [even during Biblical Shemitas]:
- Weeding [Nikush]
- Idur [Digging around roots]
- Watering [Haskah]
- Fertilizing [Zibul]
- Yibul [Cutting a Yaboles from a tree]
- Grooming the branches
- Powdering the tree with growth vitamins
- Removing rocks from on top of the roots
- Leashen: To smoke the tree to kill the worms.
May a Jew perform Melacha to the land of a gentile?
3. May one eat foods that had Melacha performed to it?
Some Poskim rule that it is forbidden to eat produce which had Melacha performed with it.
4. Melachas for loss prevention:
It is permitted to perform all Rabbinical Melachas for the sake of preventing loss or damage to ones crops or garden. This is called “Leikumeiy”. It is however forbidden to do so simply for the sake of its extended growth and nurture. This is called “Leivrueiy”.
A. May one harvest his field during Shemitah for purposes of distribution?
One may not harvest his field in the normal method. He is to harvest only small areas at a time, and preferably use his hands. One is not to cut the fruits off the trees using a regular scissor and is rather to use a knife.
B. May one cut branches off a tree for the purpose of using them?
Yes. However he must intend not to benefit the tree in the process.
May one cut Sechach during Shemitah to use for his Sukkah?
Yes. However it is best to do so in an irregular method than that used for trimming trees.
May one cut branches of a fruit tree?
One may only do so if the tree has grown its fruit at least 1/3 of their growth, or if the tree has not yet begun to produce any fruit.
Does Sechach have Kedushas Sheviis?
 Rambam 1/2; Derech Emunah 10
 Rashi and Tosafos in a number of areas; Derech Emunah ibid; Toras Hashemitah 1; See Chazon Ish 17/1
This is a Halacha of Moshe from Sinai. [Derech Emuna ibid]
 Sheves Haaretz 8/8 3-4
 See Toras Hashemitah 2/10; Ridbaz 3; Nechpah Bakesef 1/4
 Toras Hashemitah 11/37
 Toras Hashemitah 3/13
 Rambam 1/15-21; 2/2-8; Shabbos Haaretz 1/18-5
 Rambam 5/17
 Rambam 5/21; 7/14